Seventh seed Elena Dementieva won an error-strewn battle of attrition against fellow-Russian Vera Zvonareva 6-4, 1-6, 6-2 to reach the quarter-finals of the French Open on Monday.
There were 11 breaks of serve in their 25 games and the pair conjured up 78 unforced errors between them before Dementieva prevailed to book a place against another Russian, either top seed Maria Sharapova or Dinara Safina, the 13th seed.
"I feel like I'm playing a Russian championship not Roland Garros," said Dementieva, who will be playing her third Russian opponent in the last eight.
The portents for a poor quality contest were there from the start with both dropping their opening service games.
They shared further breaks before Dementieva made the crucial breakthrough by edging ahead 5-4 and then holding serve, sealing the set when Zvonareva returned long.
Dementieva's notoriously shaky serve showed the first signs of wobbling as her game collapsed in the second set and she failed to hit a single winner. Zvonareva took it in just 28 minutes.
"I feel like I've done some work, and it's really improved a little bit," Dementieva said of her serve. "It's not perfect yet, but I feel more comfortable. It doesn't make me bad or down when I'm serving now."
Dementieva, the 2004 runner-up, regained her poise in the decider, racing to a 5-0 lead and at one point reducing Zvonareva to such frustration that she smashed her racket three times into the red clay of Centre Court.
Zvonareva, who had won their previous encounter on clay at Charleston this year, finally won a game but Dementieva held her nerve.
She sealed victory with a crunching backhand winner after an hour and 48 minutes, celebrating her win with a joyous pirouette on the baseline.
"What I think that really helped me, was the match we played in Charleston in the semi-finals," Dementieva told reporters.
"I think it was a tough match, but I learned my lesson. Today on the court when I lost the second set I was trying to stay more positive, more aggressive with her, because I know she's a great claycourt player."