Auckland - Sloane Stephens claimed her second WTA tour title when she beat Germany's Julia Goerges 7-5, 6-2 in the Auckland Classic final on Saturday.
Stephens, ranked 30th in the world after being as high as 11, capitalised on a string of unforced errors by Goerges to break her serve at 5-5 in the first set.
She broke twice more in the second set at 1-1 and 4-2 before serving to wrap up the final in 77 minutes.
It capped an arduous five-and-a-half hours for the 22-year-old American who began the day having to complete her rain interrupted semi-final against former world number one Caroline Wozniacki.
That match resumed with Stephens up 5-2 in the first and she went on to win 6-2, 7-6 (7/3) before going on to claim her second title after winning in Washington last year.
Although she showed no sign of fatigue in overpowering Goerges in straight sets, Stephens could feel the effects of her marathon day.
"Finally, I'm done," she said after winning.
"It feels amazing. To win a tournament is unbelievable.
"I've played some really tough players, and to play this morning and come back to play the final is something I've never done, so I was really pleased with the way I was able to pull myself together and win."
The first set in the final went with serve until 5-5 when Goerges game fell apart.
She fought back to deuce from being 15-40 down but then had no answer to Stephens' favoured weapon, a powerful cross-court forehand, the same stroke she used to close out the match.
Although Stephens' forehand constantly troubled Goerges, the 27-year-old German's biggest problem was 33 unforced errors compared to 16 for Stephens.