WASHINGTON, D.C., USA -- Two-time Grand Slam champion Svetlana Kuznetsova staged a remarkable comeback to win the Citi Open title on Sunday, staving off four match points in the second set to defeat No.7 seed Donna Vekic of Croatia, 4-6, 7-6(7), 6-2.

"In the second set, each of us holding serve, I was some match points down, I just managed to hang in there," Kuznetsova told the media, after the victory. "I knew I was close, I could turn it around, but of course it was really tight in the second set. Then the third set, I felt [Vekic] was really down on herself and she was tired; I felt better and I found my game."

Kuznetsova, the 2014 Citi Open champion, maintains her undefeated record in the American capital, extending her streak to 11 straight wins after the engrossing two-and-a-half-hour victory over Vekic (a withdrawal against Sloane Stephens in 2015 does not count towards her win-loss record).

"This morning, somebody said I never lost here -- I didn't realize that," Kuznetsova exclaimed. "I’m just doing my job the best I can, and this week, I did pretty good for me. I played great matches."

Former World No.2 Kuznetsova has fallen to World No.128 due to injuries, making her the lowest-ranked player to hoist the title in Washington. But the 2004 US Open champion and 2009 Roland Garros titlist must now consider herself a championship threat at WTA events once again after collecting the 18th WTA singles title of her career after a rain-plagued event.

"It was a difficult week," said Kuznetsova. "Tennis is always mental, if you lose or if you win, you always gotta stay focused."

Kuznetsova had barely lost games in her four matches leading up to the final, but was challenged extremely hard by Vekic throughout the first two sets. Vekic finished with 40 winners to Kuznetsova's 34, but also had 48 unforced errors to the Russian's 36.

Vekic opened the match with solid serving and strong drop shots, and claimed the initial break for a 3-1 lead after Kuznetsova squandered a 40-15 lead. Vekic then proved her mettle by holding for 4-1 with five consecutive points from a 0-40 deficit.

In the next game, it was Kuznetsova who had to fend off a dire situation on serve, erasing two break points, which would have given Vekic a 5-1 lead. The Russian stayed a single break behind, and was rewarded when Vekic served for the set at 5-3, hitting a winning drop shot of her own to reach triple break point, and then getting back on serve after a Vekic double fault.

But the Croatian ended up with the last laugh in the opening frame, engineering a comeback at 5-4 after Kuznetsova had three game points to level the set. A stunning forehand crosscourt return winner gave Vekic a second set point in the game, which she converted when Kuznetsova fired a forehand long.

Both players were steely for a large stretch of the second set, as neither faced a break point until Vekic staved one off to hold for 4-3. But, after a love hold for 5-4, Vekic got a chance to close out the match when she held two match points on Kuznetsova’s serve. But a couple of groundstrokes got away from the Croatian, and Kuznetsova eventually held for 5-5 with an ace.

After those tense moments, the combatants did well to hold their serves and advance to the tiebreak. Kuznetsova struck first, going up a mini-break after a Vekic double fault for 3-1, and changing ends at 4-2 after a plethora of deep groundstrokes led to a forehand winner.

Vekic stayed in touching distance, and Kuznetsova gave her a lifeline with a double fault of her own for 5-5. The Russian dropped her next point on serve as well, pushing a backhand miscue into the net and giving Vekic a third match point at 6-5. But Kuznetsova crushed a forehand return winner to level at 6-6.

Vekic ended a rally with a forehand winner to set up a fourth match point at 7-6, but on the next point, the Croatian shot a makeable forehand wide to let Kuznetsova off the hook. From there, the Russian’s defense and experience led Vekic into errors, and Kuznetsova took the next two points to win the tiebreak 9-7.

Kuznetsova rolled from there, using slices and dices to frustrate Vekic even further, as the Russian swept to a 4-0 lead in the deciding set, and then held for 5-0 with her eighth ace of the match.

Vekic staged a brief fightback of her own, holding for 5-1 and then breaking an error-prone Kuznetsova at love when the Russian served for the match. But, in the next game, Vekic double faulted at 30-30 to give Kuznetsova her first match point, and the Russian refused to lose, taking the trophy after a final wide forehand by the Croatian.

"I just have next week off, I’m really happy about it, I’d like to take a couple days off," said a satisfied Kuznetsova. "Then I got a wild card to Cincinnati, so I’m really happy and thankful for that. I’m just looking forward to playing there."