Dubai Duty Free Tennis Championships updates - Day 1: Kei Nishikori and Jo-Wilfried Tsonga in first round action

Jaziri through as Tsonga retires

Malek Jaziri claimed his 100th career victory on Sunday after the Tunisian reached the second round of the Dubai Duty Free Tennis Championships following Jo-Wilfried Tsonga retired injured.

The first set was level at 3-3 when Tsonga pulled up with an arm injury while serving. The Frenchman appeared to be in discomfort the previous game but opted not to call for the trainer. This time he did but the physio was unable to help and Tsonga called time on the match.

Jaziri will take on Serbian 11th seed Dusan Lajovic in the second round.

Karatsev to face Evans

Australian Open history-maker Aslan Karatsev made a winning start to his debut appearance at the Dubai Duty Free Tennis Championships after defeating Bulgaria's Egor Gerasimov 6-4, 6-4 in the first round.

Karatsev enjoyed an historic run at Melbourne Park last month when he became the first male player to reach a Grand Slam semi-final on debut having come through qualifying.

Awarded a wild card by Dubai organisers, world No 45 Karatsev produced a solid performance to book his place in the second round, where he will face British No 1 Dan Evans.

The Russian claimed two breaks of serve in both sets, with Gerasimov breaking once in each, to ensure victory in one hour and 54 minutes.

Nishikori tames Opelka to reach second round

Japan's Kei Nishikori earned the first win of the 2021 ATP Dubai Duty Free Tennis Championships after a come-from-behind 3-6, 6-3, 6-4 victory over Reilly Opelka of the United States on Sunday.

Opelka is one of the biggest servers on the ATP Tour, while Nishikori is one of the most consistent baseline players of his generation, so it came as no surprise that the match was decided by fine margins.

Dropping serve against Opelka is never a great idea and the American made Nishikori pay when he broke the former world No 4 for a 5-3 lead. Opelka then served out to love to clinch a first set during which he lost just four points on serve.

However, Nishikori bided his time and his chance to break Opelka came in the fourth game of the second set, which he did at the second opportunity. Those were the only break points of the set as Nishikori levelled to take the match into a decider.

The third set played out much like the previous two, with both players giving little away on serve. That was until Opelka opened the door and handed Nishikori a break point in the seventh game. The former US Open finalist seized the moment to claim a precious advantage, before serving out the match three games later.

Victory earns Nishikori a second round clash with Belgian fifth seed David Goffin, who as a fast and consistent baseline player will provide a vastly different challenge to the big-serving Opelka.