American Taylor Fritz enjoyed a comeback victory over Fernando Verdasco 4-6 6-2 7-6 (1).
World number one Roger Federer showcased a rich vein of form as he eased past Serbia's Filip Krajinovic in straight sets to storm into the fourth round of the Indian Wells Masters here on Tuesday.
It was another snag in the return for world number 13 Djokovic, who admitted he lacked composure while playing in just his second event of 2018 and first since having surgery.
However, after levelling up at 2-2, Federer hurried to a one-set lead in the next four games, winning three of them to love.
In large parts of the match, Federer used the drop shot to get the Serbian off the balance.
Djokovic was beaten 6-7, 6-4, 1-6 by world No109, Taro Daniel, who had made the main draw as a qualifier.More news: Must act quickly on European investment budget - Merkel
With rivals Rafa Nadal, Stan Wawrinka and Andy Murray electing not to enter the tournament, and Novak Djokovic and Kei Nishikori both out of the running, the path appears clear for the Swiss to win a record sixth Indian Wells title.
"In Rotterdam I played five matches in a row", he said. "I mean, I just completely lost rhythm, everything".
Federer staved off a set point in the tiebreak to beat Delbonis 6-3 7-6 (6).
In the women's section at Indian Wells, Simona Halep took pride in rallying past 19-year-old Caroline Dolehide, while Petra Kvitova's remarkable win streak skidded to a halt against another United States teen.
Coric will play the victor of the match between Fernando Verdasco and American Taylor Fritz in round four. I am on a good run right now and I want to maintain that. "And even though you don't have pain, you are still thinking about it, because it has been something that I have been feeling and dragging for over two years", Djokovic said. So it was definitely nerve-wracking kind of, but I was enjoying it so much out there and I was playing my best.