Geneva | Novak Djokovic celebrated his 37th birthday by beating unseeded Yannick Hanfmann 6-3, 6-3 to reach the quarterfinals at the Geneva Open.

It was the 1,100th victory for the World No. 1 at ATP tournaments.

Djokovic rallied from 3-0 down in the final set by winning six straight games. He converted his second match point when Hanfmann's forehand hit the net.

The 32-year-old German broke Djokovic in the second game of the set when Djokovic struggled with his first serve.

The second-round match had earlier been suspended by rain with Djokovic trying to serve out the first set 5-3, deuce.

The record 24-time Grand Slam champion wasted a set point and had to save four break points before the match was interrupted by rainfall.

He had to save another break point after play resumed before serving out the set with an ace.

Hanfmann had eliminated Andy Murray in the first round 7-5, 6-2.

Djokovic received a wild card at the clay-court warmup event for the French Open.

Seeking his first title of the season, Djokovic will next face either Denis Shapovalov or Tallon Griekspoor.

The Geneva Open final is scheduled for Saturday, one day before main draw play starts at Roland Garros, where Djokovic is the defending champion.