Marat Safin advanced to the quarterfinals of the ATP Countrywide Classic with a 6-2, 2-6, 6-4 victory over George Bastl.
Safin, the No 3 seed, got past the second round of the tournament for the first time in four tries and is on course for a possible semifinal meeting with No 2 seed James Blake.
They are the highest seeds remaining following No 1 Fernando Gonzalez's loss to Zack Fleishman on Tuesday.
A former world No 1, the 27-year-old Safin finally took control of the match at the Los Angeles Tennis Center at UCLA midway through the final set. He got a service break to take a 4-3 lead, then fought off three break points and held serve with a 130 mph ace to go up 5-3.
He got the win when Bastl, of Switzerland, hit a forehand return long.
Safin was joined in the quarterfinals by Nicolas Kiefer, who continued his comeback from wrist surgery with an efficient 6-3, 6-2 win over Igor Kunitsyn. It was just Kiefer's second hardcourt match in more than a year.
In the quarterfinals on Friday, Kiefer will face fellow German Michael Berrer, who advanced with a 6-3, 7-5 win over qualifier Ricardo Mello of Brazil.
Also through to the quarterfinals is Korea's No 1 player, Lee Hyung-taik, the No 7 seed. He beat Wesley Moodie, who retired with a back problem while trailing 6-2, 3-0. Lee had won seven games in a row at that juncture, and had lost just one point in the second set.