Novak Djokovic had to fight in his first competitive match for more than a month on Tuesday as he battled past Martin Klizan at the Mexican Open in Acapulco.
The world no. 2 took 90 minutes to see off the veteran Slovak 6-3, 7-6(4) at the ATP World Tour 500 event.
Djokovic was made to work early on, saving four break points in his first three service games in his first match since a second-round exit at the Australian Open in Melbourne.
But he held firm and then earned a break in the sixth game to lead 4-2 before serving out for the first set.
Klizan then finally got his break in the sixth game of the second set only for the Serb to break back straight away and then take the set and the match in the tie-breaker.
Djokovic will now face Juan Martin Del Potro of Argentina in the second round after he defeated American teenager Francis Tiafoe 6-4, 3-6, 7-6(1).
— Next Gen ATP Finals (@nextgenfinals) February 28, 2017
In other first round action, defeated Australian Open finalist Rafael Nadal defeated Mischa Zverev of Germany 6-4, 6-3 while number eight seed Marin Cilic took three sets to get past Buenos Aires winner Alexandr Dolgopolov 6-3, 4-6, 6-0.
Cilic hit 14 aces in the win and will face compatriot Borna Coric in the next round.
Australia’s Nick Kyrgios advanced into the next round after beating David Sela of Israel in three sets, 3-6, 6-3, 6-3, while compatriot Bernard Tomic controversially retired from his singles match after losing the first set tiebreaker to America’s Donald Young.
Tomic returned to court just two hours later for his men’s doubles match.
Fourth seed Dominic Thiem of Austria got past Frenchman Gilles Simon 7-6(7), 6-3 and, in an upset, the unseeded Yoshihito Nishioka of Japan beat American seventh seed Jack Sock 3-6, 6-2, 6-1.