Top seed Dinara Safina came through another shaky match at the US Open to reach the third round with a win over Kristina Barrois.
The world number one had been less than impressive in her first-round win over wild card Olivia Rogowska, coming from 3-0 down in the final set to beat the Australian.
Her second round match against the world number 67 from Germany was similarly frustrating at Louis Armstrong Stadium as the Russian took two hours and 13 minutes to eke out at 6-7 (5/7) 6-2 6-3 victory.
Safina, who gave up 15 double faults and committed 38 unforced errors to 36 winners, had been out of sorts from the start, opening the match by having her serve broken before breaking straight back.
The first set went with serve from there and Barrois just managed to hold her serve to take it into a tiebreak.
Safina was again in trouble as Barrois took a mini-break to lead 5-4 and her serve let her down at the decisive moment when a double fault, her sixth, gifted the German the set after 57 minutes, the Russian throwing her arms up in frustration.
Safina came out for the second set all steamed up and broke Barrois to love to take control but at 2-1 up the top seed again let her frustration get the better of her, serving another fault and throwing her arm up in disgust before netting a booming forehand as the set got back on serve.
That changed quickly though as Safina stepped up a gear and took the next three games in a row and served for the set at 5-2, pulling level with Barrois at 1-1 when the German mis-hit a crosscourt backhand wide.
The Safina serve was continuing to undermine the Russian and she began the third set as she had the opener, by failing to hold the second game, racking up her 13th double fault of the match in the process.
Luckily for her, Barrois was serving just as poorly and she was broken in the next game.
Safina levelled up the set at 2-2 with her next hold and at 3-2 down produced perhaps her best service game of the match so far, back to back aces and then another big serve angled into the Barrois backhand helping her to the game.
The victory finally looked assured but Safina was not out of the woods yet. At 4-3 up she gave herself more work to do as she faced a triple break point, once again digging herself out of trouble to get to within a game of advancing to round three.
Then it was Barrios’ turn to crumble, the German quickly offering three match points and surrendering meekly at the first one, a double fault handing the win to a far from convincing Safina.