Under the series' playoff system, the points have been reset and the quartet start equal - whichever of them is first over the line after 267 laps (or more if there's overtime) is this year's champion.
Thanks to the Friday rain that forced the finale schedule to be rewritten, they start 1-2-3-4 on the grid with qualifying having been cancelled.
The weather also meant the whole field has had very little mileage going into the decisive race, with just a single 50-minute practice session held on Saturday.
Here's what the title contenders are thinking going into their biggest race of the year, and what our writers think of their chances.
Joe Gibbs Racing Toyota
2010 Cup runner-up
6 wins this year
Recent form: 1st-28th-4th-1st-3rd
3rd in practice
Hamlin went into last weekend's Phoenix race knowing victory was vital after his Texas crash left him on the cusp of elimination from the title race.
He won then, and that makes him confident he can do the same again this weekend.
"That was our win-or-go-home race. We performed at an incredibly high level," Hamlin says of Phoenix.
"We have now a free weekend to go out there and have fun and keep doing what we've been doing.
"We'll have a chance by the end of the night because we have all year long as long as we do the same thing."
Hamlin dominated at Phoenix, leading nearly half the race and holding an advantage of 10 seconds at times.
"I was pretty down after Texas. I knew it was on me," he reflected.
"I've been eliminated from the playoffs many, many ways. The craziest [stuff] has happened to me to keep me from winning championships.
"I was going to hate that I was going to be responsible for ending our chance at a championship."
The 38-year-old has already declared his 2019 season a success regardless of the championship outcome.
He began the year coming off the first winless season of his Cup career but kicked off 2019 by winning the Daytona 500 for the second time.
Earning the right to be one of four drivers competing for the series championship in this format, Hamlin believes, is an accomplishment as important as winning the title itself.
"One race, winner take all, anything can happen. If you have a mechanical failure on lap 25, does that mean you're not good enough? You made the final four," he said.
"Making the final four is the culmination of your whole year. That is what deems your year a success: you made it to Homestead. Every single driver here will tell you that.
"No one is going to discount their year based off the outcome on this weekend."
Our verdict on Hamlin
Charles Bradley: Before the season I had Harvick tabbed as champion, but I think I'm going to be proved wrong! It's been such a misfiring year for Stewart-Haas Racing, certainly compared to the Joe Gibbs-run Toyotas. So, unless SHR hits the jackpot like at Texas a few weeks ago, I'm not convinced his car is going to be in the right downforce window for Homestead, whereas Gibbs gets it right more often than not.
I just have a sneaky suspicion that Hamlin is going to shock us all again; if he can be as relaxed this Sunday as he was when I spoke with him on race day morning at the Daytona 500, he can deliver like his sponsor FedEx.
Stewart-Haas Racing Ford
4 wins this year
Recent form: 5th-1st-7th-9th-17th
9th in practice
Harvick's road to the 'championship four' has been a difficult one after a "mediocre" start to the 2019 season.
It took 20 races before Harvick - and his Stewart-Haas team - even scored a race win. But three more triumphs, including the Texas playoff race, secured his place in the final four.
That slow start created "a lot of doubts" within SHR.
"The season the results weren't bad, we had mediocre results for what we expect as the #4 team," said Harvick.
"It's been a grind and a battle week‑in and week‑out as to what do we need, what do we need to do differently, because the thought process is just so much different than what we have ever done before.
"As an organisation we have had to struggle through that and it's been a grind. I would be lying to you if I told you it wasn't taxing on everybody, the amount of work that has been put in to get to this point.
"But the good part about working at Stewart‑Haas is you have a group of racers and they want to be competitive and they're not satisfied with finishing fourth like we did I think five or so races in the first seven or eight.
"You have to be able to lead laps and you have to get top fives in order to have a chance at winning races. And we just weren't at that point in the first half of the year and I feel like we have still been sporadic in the style of racetrack that we can lead laps on."
Harvick is the outlier in this title fight as his three rivals all come from the same organisation: Joe Gibbs Racing. But he sees an advantage in being Stewart-Haas's sole title contender.
"For us it's very simple, there's no worries about making the sponsor mad or making another team member mad," he said.
"It's 'how do we get Stewart‑Haas Racing another championship?' and all four teams [SHR crews] have bought into that and want to do the exact same thing because it's good for Stewart‑Haas Racing.
"Our guys have worked their butts off on really all the cars over the last four weeks, trying to do everything that they can to continue to learn about the cars and I think we're still learning.
"They would be mad at me for saying this, but it's still a little bit of a guess as to where you're at.
"But it's definitely been nice to not have to deal with any politics internally or anything. It's just 'what do you need? Let's do it' and everybody's worked really hard. So there's nothing to navigate for us."
Jim Utter: While he's not who I would have envisioned picking six months ago, I'm going with Harvick as the most likely champion for a few reasons.
In the past couple of months, his crew has got a much better handle on intermediate tracks, which most recently led to his win at Texas. Also, the new tyre combination at Homestead this weekend was used at Chicagoland and Darlington this season and Harvick's average result from those two races - 9.0 - is the best of any of the title contenders.
Joe Gibbs Racing Toyota
7 wins this year
Recent form: 6th-6th-1st-6th-26th
2nd in practice
Truex has won more Cup races than anyone else in his first season with JGR.
The knockout style playoff format has never produced a repeat champion since its 2014 introduction, but Truex has come closest - finishing second last year as he tried to defend his '17 title.
Three of Truex's seven 2019 wins have come during the playoffs but he reckons when it comes to championships "it's harder to win now than ever" and "the odds are a lot worse in this system" with everything ultimately decided on one race.
"To have the opportunity again is huge," he added. "You just want to put your best foot forward and leave here knowing you gave it all you had, you didn't screw up, step on your foot, put your foot in your mouth or anything stupid.
"A second championship would be indescribable right now for me."
To win it all, he has to overcome two of his three JGR team-mates.
"Away from the track, I think we get along well," he said of Busch and Hamlin.
"I would say we're not really good friends. We don't hang out, do stuff away from the track with each other.
"The mutual respect is something that stands out to me. We've raced against each other for a long, long time. You learn to respect guys like that.
"I respect certainly what they've done, what they're capable of today. I know how tough they are to beat."
Although there is an open book policy at JGR, that doesn't mean all three of its title-chasing cars will be the same going into Sunday's race.
"It's not like we show up at the track and we all have the same car, the same set-up, the same thought process, the same driving style," Truex explained.
"Yeah, we build cars together, then we go through the week and the crew chief and engineer say 'I want to go down this road'. The other one says 'I want to go here'. You end up at different places. Your decisions throughout the weekend take you different places.
"That's all open information. It's going to continue to be that way."
There was a time when the idea of Truex as a potential two-time champion would have seemed implausible, but his career trajectory took a very sharp turn after joining Furniture Row Racing in 2015.
In his first 348 Cup starts, he won just two races and finished no higher than 11th in the standings after nine full-time seasons.
But since 2015, he has won a further 24 races and made the championship quartet four times. His numbers, once unremarkable, are quickly becoming Hall of Fame-worthy.
"I definitely don't take this for granted," he said of his surprise rise to the top.
"I love this opportunity. I'm having the time of my life with this team.
"It's amazing to be here having another opportunity at a championship. I still have a hard time believing I've already got one, let alone here we are with a really, really good chance I feel like at a second."
Nick DeGroot: Hamlin has momentum on his side but if anyone is going to beat him it's going to be his team-mate Truex.
He has more wins than any driver this year and drove a solid race at Phoenix with "half a team and an old car". Truex and crew chief Cole Pearn are a combination that have done this before, winning the 2017 title and coming just one position short of going back-to-back in '18. And that was before they joined the juggernaut that is Joe Gibbs Racing.
Joe Gibbs Racing Toyota
4 wins this year
Recent form: 2nd-7th-14th-3rd-19th
1st in practice
For half a decade now, Kyle Busch has been a contender for the NASCAR Cup Series championship.
In a playoff system that has required both winning and consistency for success, that's a remarkable statement for one driver and team.
The frustrating part for Busch is the fact only once has he been able to actually come away with ultimate prize, the series title.
Most would agree it's harder than ever to get in position to be one of the four drivers eligible for the series championship in the season finale. For Busch, the title itself has been even more elusive.
"Jimmie Johnson scooping up five [championships] in a row was certainly hard for the rest of us to beat," Busch said.
"They were on top of it and on top of their game, in different cars for that matter, but that just means we all didn't do the job and put it all together the way we needed to.
"I look at 2016 as a missed opportunity. Jimmie won that one for seven [championships]. So, is this Kyle's time? Being here five years in a row, I would certainly like to think so."
Busch began the 2019 season on a roll, winning four of the first 14 races and amassing a pile of playoff points that would ultimately assist him in his path to Homestead.
But he's failed to reach Victory Lane since his June win at Pocono. His best playoff performance so far came at Phoenix last week, when he was second to Hamlin.
It's been no secret Busch isn't a big fan of the new Cup aero package for this season and there have been times of frustration as his team struggled to get a handle on what he needs to make the 2019 car work for him.
He has maintained a guarded attitude about his title chances in the second half of the season, and admitted it would be "pretty defeating" for his streak of being in title fights but losing them to continue.
"We'll fight as hard as we can, do the best job we can, exactly what we did [at Phoenix] - we just weren't good enough [to win]," he said.
"This week, we'll just have to make sure that we are. Somehow, some way.
"If it works out, it was meant to be. If it doesn't, then it's not. Hopefully the sun will come up for another day."
Matt Beer: When he won his title in 2015, Busch missed 11 races with a broken leg. So he knows how to peak at the right time in the current Cup format. The 21-race winless streak he's on right now needn't mean he has no chance of winning the one that matters - especially as he was Hamlin's closest challenger last week.
He's the most tenacious of the title rivals and probably the one most likely to be willing to get 'creative' to get the job done.
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