LOS ANGELES (AP) _ Xavier Malisse ended his personal losing streak against Tommy Haas on Wednesday, upsetting the defending champion of the Mercedes-Benz Cup, 1-6, 6-3, 6-4.
Malisse, 25, of Belgium, had lost four straight and eight of 10 overall to Haas, who had been sidelined for six weeks by torn right ankle ligaments before opening play here on Tuesday.
The victory, which moved Malisse into the quarterfinals, marked the first time in nine tournaments he managed to win back-to-back matches. He had beaten Hyung-Taik Lee on Monday night.
Earlier Wednesday, Juan Ignacio Chela, No. 2 seed Dominik Hrbaty and Ricardo Mello advanced to the quarterfinals.
Chela beat Dmitry Tursunov, 3-6, 6-4, 6-2; Hrbaty overcame Jan Hernych, 6-4, 6-2; and Mello was a 6-3, 6-1 winner over qualifier Amir Hadad.
Malisse won only two points more than Haas, 76-74, but was able to overcome the loss of the first set with the help of 18 aces.
"I changed my motion a little bit,'' said Malisse, who had an ice pack taped to his right forearm after the match. "I've been working on it and it's coming along. I got a good rhythm and I felt good.''
Haas said the loss wasn't a result of conditioning lost during his long layoff, but of his failure to take advantage of the chances he had to take control.
"I thought I was playing pretty solid,'' he said. "There were just a few easy mistakes here and there and not using my chances. That's the key in every match. His serving probably won the match for him.''
Tursunov got into the tournament as a ``lucky loser'' from qualifying when both Taylor Dent and Mardy Fish withdrew Tuesday night. Tursunov took advantage of the opportunity by beating Noam Okum in straight sets, then carried some of that momentum into the match with Chela, winning the first set by taking the final four games.
Tursunov also won the opening two games of the second set before Chela regrouped.
Hrbaty, who will face Mello in the quarterfinals on Friday, converted five of six service break opportunities against Hernych.
"I felt I played really well from the baseline, I didn't make too many mistakes and I served well,'' Hrbaty said. "I was happy with my game today.''
Mello had little trouble defeating Hadad, a qualifier who won his first ATP Tour match of the year on Monday. Mello, ranked No. 50 and now 13-14 this year, raced out to 4-0 and 5-0 leads in the two sets.
"It was a match that I played very well from the first point to the last,'' he said. ``I was very focused. For me, winning two matches in the same week is very good.
"It gives me confidence. I hope for the same in my next match, the same focus and a good match. It's a tough match against Hrbaty. I'll have to play my best tennis.''