ESPN Tennis

BALI, Indonesia -- Flavia Pennetta of Italy converted her anger at opponent Anastasia Rodionova into aces, beating the Russian 6-3, 7-5 to reach the quarterfinals of the Bali Classic on Thursday.

Pennetta, the No. 3 seed, was incensed when Rodionova called for medical attention when leading 5-2 in the second set and waved away the explanation from an official.

After Rodionova applied ice to her neck and had her blood pressure checked she continued but then called for attention again after losing the next two games. When play resumed a second time Rodionova barely competed, allowing Pennetta to fire five aces in her next two service games to complete her victory.

"I was angry," Pennetta told reporters. "A match like this is not good for the public. The last three or four games were very bad to watch.

"For me, if you are like this on the court it is better that you go. If you have any problem and you cannot play, you cannot play. That's it. You go."

Pennetta struggled with consistency, and her fragile advantage in the first set was exposed in the second. Having broken to lead 5-3 on her sixth break point she had to fight off a break point as she served for the first set, and then fell behind 4-0 in the second.

"I was 4-0 down and I didn't breathe at all," said Pennetta, blaming a long rally at the beginning of the set. "I was so tired. At 4-0 I started to feel a little better and breathe a little more and the match started to change."

There was no such drama for No. 4 seed Nadia Petrova of Russia, who claimed a 6-1, 6-1 win over Italy's Tathiana Garbin.

Petrova faced seven break points, saving them all, and converted only five of 12 break points she held on Garbin's serve.