Third seed Alexander Zverev has been knocked out of the Indian Wells Masters by Tommy Paul in his first game since his expulsion from last month's Mexican Open for unsportsmanlike conduct.
Unseeded American Paul triumphed over the German 6-2 4-6 7-6 (7-2) in two hours and 17 minutes, rallying back from a break down in the final set.
Paul hit less winners, 26-21 to Zverev but made less unforced errors 25-19, while his serve and volley game was a key feature.
"I played a really high level today," Paul said during his on-court post-game interview. "The last time I played him, I played well, I put pressure on him so I knew how i wanted to play so I came out and executed him well.
"I played well when it came down to the breaker, so I'm pretty happy with my performance."
Zverev had not played since being expelled in Acapulco after a stunning outburst where he struck his racquet on the umpire chair several times after a doubles defeat.
Ninth seed Felix Auger-Aliassime was a major casualty, going down to Dutchman Botic van de Zandschulp 7-6 (7-4) 6-7 (4-7) 6-3 in three hours and 15 minutes.
The Canadian had 36-27 winners but was let down by 43-26 unforced errors, along with converting only two of his 10 break points.
Van de Zandschulp had failed to take three match points in the second set but showed composure to finish the job in the third.
Wild card Andy Murray was also eliminated in the second round, blowing three set points in the first set before going down to 31st seed Alexander Bublik 7-6 (11-9) 6-3 in two hours and one minute.
Last year's Wimbledon runner-up and Italian sixth seed Matteo Berrettini needed more than two hours to get past world number 86 Holger Rune 6-3 4-6 6-4.
Seventh seed Andrey Rublev defeated Dominik Koepfer 7-5 6-4 to extend his win streak to 10 matches, while 11th seed Hubert Hurkacz beat Oscar Otte 6-3 3-6 6-3.
Other seeds to be eliminated were 22nd seed Aslan Karatsev who went down 7-6 (7-5) 6-4 to American Steve Johnson, while 24th seed Marin Cilic lost 6-7 (7-9) 6-3 7-6 (8-6) to Miomir Kecmanovic.