* Italian overcomes recent injuries
* She faces American Pegula in final
* Pegula tops Kalinskaya in three sets
* Russia's streak in final ends (Adds details, quotes)
Aug 3 (Reuters) - Italy's Camila Giorgi ended American teenager Caty McNally's surprising run with a 7-6(5) 6-2 victory in the semi-finals of the Citi Open in Washington on Saturday.
The big-hitting Giorgi, on the comeback trail after wrist and ankle injuries, prevailed in an opening tie break, then dominated the 17-year-old in the second set, winning five games in a row.
The Italian will face another American, Jessica Pegula, as she plays in her seventh WTA final on Sunday.
Pegula won five consecutive games off Russia's Anna Kalinskaya in the third set to win 6-3 3-6 6-1.
"I tried to be more aggressive," Giorgi told Tennis Channel when asked about the sharper play after the tiebreak.
Giorgi had not won a match since the Australian Open and had competed in only three tournaments due to the injuries.
"For three months I didn't play tennis. Every day I was in the gym," she said. "It was not easy to start from zero."
But Giorgi has lost only one set this week in ending the dream of McNally, who had ousted fourth-seeded Hsieh Su-wei on Friday.
She will be going for third WTA title, the last coming in Linz in 2018. Pegula, seemingly inspired by a 10-minute heat break between the second and third sets of her match with Kalinskaya, delivered four of her nine aces and won all 12 of her first service points in the final set.
"I knew if I could start off strong in the third set, I could get her," said Pegula, who is the daughter of Terry Pegula, the owner of the National Football League's Buffalo Bills and National Hockey League's Buffalo Sabres.
The 25-year-old dominated the first set, but Kalinskaya levelled the match in the second, taking the final three games, before the big swing in Pegula's favour.
Kalinskaya's loss ended Russia's bid for a third consecutive title in the U.S. capital as Ekaterina Makarova and Svetlana Kuznetsova had won the previous two tournaments. (Reporting by Gene Cherry in Raleigh, North Carolina Editing by Christian Radnedge and Pritha Sarkar)