Top seeds David Nalbandian and Nicolas Massu were beaten in the quarter-finals of the Vienna Trophy on Friday.

Nalbandian, seeded one, bowed out 6-4, 2-6, 6-3 to sixth seed Guillermo Canas in an all-Argentine clash. Second seed Massu of Chile was beaten 6-4, 6-3 by 32-year old Italian Davide Sanguinetti.

Canas has now won 21 of his last 23 matches, but the outcome of his two hour 18-minute battle with Nalbandian remained in the balance right to the end.

The entire match featured exchanges of the highest quality after Canas converted his fifth break point to lead 2-0.

Nalbandian broke back as Canas served for the set at 5-3, but then lost his serve again and conceded on the fourth set point.

Two breaks for Nalbandian in the second set levelled the match but three breaks in the final set left Canas leading 4-2. Even at that late stage Nalbandian had an opportunity to turn the match around, but Canas fought off two break points to hold for 5-2.

"It was a tough match and we both played very good tennis," said Canas.

Sanguinetti broke twice in his match with Olympic champion Massu to lead the second set 3-0, but Massu fought back and held a break point to level at 3-3.

The Italian saved that with a forehand volley, and then broke a final time for the match when Massu hit a double-fault and then put a forehand wide.

Sanguinetti said he was not too concerned as Massu threatened a recovery.

"I knew every game that he was serving I had so many break points," said the Italian. "I felt that I was playing too good, I was too relaxed to get scared and lose the game and the match."

Massu said: "I think I had good chances but I didn't play my game today. If you have no concentration it's difficult."

In the other quarter-finals Germany's Tommy Haas defeated American Robby Ginepri 4-6, 6-3, 6-4 and eighth seed Felicano Lopez of Spain earned his fourth victory in five meetings with third seeded German Rainer Schuettler, winning 6-4, 6-4.