World No1 Roger Federer finished off Federico Delbonis in a rain-disrupted match on Sunday to reach the third round at Indian Wells as five-time champion Novak Djokovic was toppled.
Federer returned on Sunday afternoon and needed an hour to close out his second-round victory 6-3 7-6 (8/6).
His title defence got off to a soggy start on Saturday night when play was suspended because of rain, with Federer up a set and tied 2-2 in the second.
The clouds rolled in just before the start of the match and after a short delay to start the first set they managed to play until the heavy rains came in the second. After a 90-minute delay organisers suspended play for the night.
Federer is making his 17th appearance in the California desert and is assured of remaining world No1 if he makes it to the semifinals. He extended his 2018 win streak to 13 matches and has only dropped three sets from 34 played in 2018.
He will face 25th-seed Filip Krajinovic in the third round.
Federer and 10th seed Djokovic both came into the tournament seeking to become the first six-time winner of the event. But Djokovic fell at the first hurdle with a shock loss to Japanese qualifier Taro Daniel, who sent the out-of-sorts Serb tumbling with a hard-fought 7-6 (7/3) 4-6 6-1 victory.
It was another snag in the return for world No13 Djokovic, who admitted he lacked composure while playing in just his second event of 2018 and first since having surgery.
He said it felt like the "first match I ever played on the tour. I mean, I just completely lost rhythm, everything."
Djokovic is making a cautious return to the ATP Tour after stopping his 2017 season following Wimbledon due to a right elbow injury. He lost to Chung Hyeon in the Australian Open fourth round in January before undergoing the surgery.
Djokovic scrambled to win the second set on Sunday but the rust from the lay-off was evident as he made 62 unforced errors overall. He had four aces but served poorly overall, making four double faults.
"It is still early stages for Novak coming back and the first one after surgery. He’s only going to get better from here," Federer said
In other men’s matches, Argentine Juan Martin del Potro beat Australian teenager Alex de Minaur 6-2 6-1 and set up a third-round showdown with Spaniard David Ferrer, who defeated Tennys Sandgren of the US 6-2 7-6 (7/3). World No3 Marin Cilic beat Hungary’s Marton Fucsovics 7-5 6-3.