Meghan Markle cheers on Serena Williams at U.S. Open women's singles final

SHOWS: NEW YORK, NEW YORK, UNITED STATES (SEPTEMBER 7, 2019)(STILL PHOTOS-MUTE)(USA TODAY SPORTS IMAGES - Broadcasters and Digital: MUST COURTESY 'USA TODAY SPORTS IMAGES')

1. STILL PHOTO OF MEGHAN MARKLE (IN SECOND ROW WITH BLUE DRESS AND WHITE JACKET) CLAPPING DURING U.S. OPEN WOMEN'S SINGLES FINAL BETWEEN SERENA WILLIAMS AND BIANCA ANDREESCU

2. STILL PHOTO OF MARKLE CLAPPING DURING MATCH

3. STILL PHOTO OF MARKLE STANDING AND CLAPPING

4. STILL PHOTO OF MARKLE WITH SERENA'S MOTHER ORACENE PRICE

5. STILL PHOTO OF MARKLE WITH SERENA'S HUSBAND ALEXIS OHANIAN

STORY: Canadian teenager Bianca Andreescu claimed her first Grand Slam title in a hard-hitting and nerve-jangling 6-3 7-5 win over Serena Williams on Saturday that put the brakes on the American's bid to equal the all-time record.

Andreescu matched Williams' power throughout the slugfest and kept her composure under intense pressure to fend off a late comeback from the six-times U.S. Open champion.

The 19-year-old dropped her racket after hitting a blistering forehand return winner on match point to seal victory at Arthur Ashe Stadium and collapsed on her back after embracing her defeated opponent.

Andreescu, the first Canadian to win a major in the professional era, prevented Williams from equaling Margaret Court's record of 24 Grand Slam singles titles.

Williams, who has been denied the milestone in four slam finals since claiming her last major title at the Australian Open in 2017, was gracious in defeat.

The fearless Andreescu pressured Williams from the outset, electing to receive after winning the coin toss and immediately breaking her childhood idol.

Shouting "come on" after winning key points, Andreescu's vicious forehands kept Williams on the back foot while costly errors, including a double fault on set point in the first, put the American in an early hole.

With her back against the wall trailing 5-1 and facing championship point, Williams mounted a spirited comeback to draw level at 5-5, leading to deafening roars from the packed crowd in the biggest tennis stadium in the world.

Yet Andreescu, who covered her ears at times, regained her steely composure to cross the finish line.

(Production: David Grip)