Top seed Vera Zvonareva fired nine aces on her way to a 6-2, 6-3 win over Germany's Anca Barna in the second round of the Thailand Open in Pattaya on Thursday.
Spain's Conchita Martinez won the last four games to defeat Croatia's Silvija Talaja 7-5, 2-6, 7-5 for her place in the quarter-finals.
Third seed Martinez struggled to establish any kind of rhythm or consistency. The 32-year-old twice had to recover a break of serve but she took the first set when Talaja hit her fourth double fault.
A forehand error from Martinez in the second set gave Talaja a 3-2 lead and the Croatian broke again to love for 5-2.
Talaja failed to serve out the match at 5-4 in the third and Martinez saved two break points at 5-5 before taking victory.
Russian Zvonareva's serve and forehand did the most damage against Barna but after breaking to a 4-1 lead in the second set the 20-year-old from Moscow suffered a scare when she lost the next eight points.
"Maybe I was rushing myself a little bit, trying to win the points easy," Zvonareva said. "I had a couple of unforced errors, but I held myself against her at 4-3."
She added that trying to win points on her serve was an important part of her tactics.
"It was really important, especially against Anca because she runs a lot of balls down and sometimes it's important to finish the point pretty quick."
"I was just trying to place it really well because she's a lefty and so it's important sometimes to serve to her backhand," said Zvonareva.
"This court takes the spin really well, so I put some spin on the ball. It's slow but it bounces so high and in a different direction so it's really hard to return."
Eighth seed Virginia Ruano Pascual of Spain beat Germany's Marlene Weingartner 1-6, 6-1, 6-4 and Israel's Shahar Peer defeated fellow qualifier Akgul Amanmuradova from Uzbekistan 6-4, 6-2.
