World number one Novak Djokovic was a comfortable winner at the Dubai Duty Free Tennis Championships on Tuesday, while Australian Bernard Tomic retired after just five games.
Tomic, a quarter-finalist in Marseille last week, was trailing Romanian Victor Hanescu 2-3 in the opening set before he pulled the pin – citing general illness as his reason for retirement.
Djokovic was on court for just 67 minutes as he defeated fellow Serbian Viktor Troicki in straight sets, 6-1 6-4.
The top seed was impressive in the first-round match, winning 82 percent of points on his first serve while he also made four breaks from nine opportunities.
Troicki fired six aces but his chances to break were limited such was Djokovic's dominance.
French fifth seed Jo-Wilfried Tsonga was shocked by countryman Michael Llodra in the upset of the day.
Tsonga, who beat Tomas Berdych of the Czech Republic in the Open 13 final in Marseille last week, slumped to a 6-7 (3-7) 2-6 loss in just 79 minutes.
Llodra made three breaks and served well to produce a terrific win.
Meanwhile, world number seven Juan Martin del Potro of Argentina came from behind to beat Cypriot Marcos Baghdatis.
The fourth seed won an epic that lasted almost two-and-a-half hours, triumphing 4-6 6-4 7-6 (7-4).
Baghdatis was on form throughout the match, hitting 11 aces and winning 84 percent of points on his first serve.
That enabled him to take the first set and although del Potro's response was impressive, a thrilling final set was on the cards.
Both players made two breaks during the set, forcing the match to a tiebreak with del Potro eventually successful.
In other matches, third seed Berdych brushed aside Rajeev Ram of the United States, winning 6-1 6-3.
Russian Nikolay Davydenko stunned Serbian sixth seed Janko Tipsarevic 6-0 7-5, while Spaniard Marcel Granollers prevailed 6-3 6-1 against compatriot Albert Montanes.
German Tobias Kamke won 4-6 6-4 6-4 over Kazakhstan's Mikhail Kukushkin, and Russian Dmitry Tursunov rallied to beat Czech Jan Hajek 4-6 6-1 6-2.