Former two-time champion Andre Agassi advanced to the second round of the Cincinnati Masters when Mardy Fish retired in the third set with a back injury on Monday.
Agassi, the last back-to-back winner in 1995/96, was leading 4-6, 7-6 (3), 4-1 when Fish quit.
Fish was the beaten finalist last year to Andy Roddick and had won his only previous match against Agassi in the San Jose semifinals in February.
He broke 10th-seeded Agassi in the ninth game and completed the first set on his fourth ace. In the second-set tiebreak, Agassi broke for 2-1 and the 7-3 clincher. But at 1-1 in the third, Agassi won the three straight games before Fish’s injury worsened.
In other matches, 2002 champion Carlos Moya and French Open winner Gaston Gaudio also progressed, but number eight Rainer Schuettler and number 16 Andrei Pavel were eliminated.
Carlos Moya, who beat first-seeded Lleyton Hewitt in the 2002 final, overcame British qualifier Arvind Parmar 3-6, 7-5, 6-2 by winning the final four games of the match, and ninth-seeded Gaudio dispatched United States wild card Jan-Michael Gambill 6-4, 6-2.
Tommy Haas broke in the last game to beat German countryman Schuettler 6-3, 1-6, 6-4 for the first time in five career meetings.
Schuettler, also ranked number eight, lost his sixth consecutive match on hard courts since February.
Haas next faces Sargis Sargsian of Armenia, who beat Swiss qualifier Michel Kratochvil 2-6, 6-2, 7-5.
Wayne Arthurs of Australia, a late replacement in the draw for David Sanchez of Spain, upset 16th-seeded Pavel of Romania 7-6 (5), 6-3.
Argentines Guillermo Coria and David Nalbandian, set to be seeded numbers three and six, withdrew with respective shoulder and elbow injuries. — Sapa-AP