Top seed Carlos Alcaraz moved into the Indian Wells Open quarter-finals after Jack Draper retired down 6-2 2-0 due to an abdominal injury in their last-16 clash on Tuesday.
Alcaraz was in control, winning the first set in 36 minutes before racing to a 2-0 lead inside 10 minutes before the Briton withdrew. Draper had battled the injury in the latter stages of Monday's win over Andy Murray.
Despite that, the Spaniard looked in good touch, setting up a quarter-final meeting with eighth seed Felix Auger-Aliassime, who has a 3-0 head-to-head record against him.
"I felt the ball really well. I'm really happy with that part," Alcaraz said. "I would say I returned well, I hit great shots. I finished the match with confidence in my shots, to come into the next round with more confidence."
Auger-Aliassime saved six match points in a dramatic triumph over 17th seed Tommy Paul to reach the last eight, winning 3-6 6-3 7-6 (8-6) in two hours and 48 minutes.
The Canadian trailed 0-40 on serve at 5-6 in the deciding set before winning the next five points. He repeated that feat, down 3-6 in the tie-break, capitalising on his first match point. Auger-Aliassime hit 31 winners for the match, along with 51 unforced errors.
Fifth seed Daniil Medvedev fought back from a set down and a rolled ankle to progress past Alexander Zverev 6-7 (5-7) 7-6 (7-5) 7-5 in three hours and 10 minutes.
Medvedev rolled his ankle in the sixth game of the second set, going down in pain but played on, in his longest-ever three-set match. The victory is the Russian's 17th in a row. Zverev committed 50 unforced errors across the match.
The Russian will take on Alejandro Davidovich Fokina in the last eight, with the Spaniard winning 6-3 6-4 over Chilean qualifier Cristian Garin.
Jannik Sinner cruised past Stanislas Wawrinka 6-1 6-4 in one hour and 39 minutes to move into the last eight where he will face reigning champion Taylor Fritz. The American won 6-4 6-3 over Hungary's Martin Fucsovics in one hour and 41 minutes.
British 10th seed Cameron Norrie will play 14th seed Frances Tiafoe in the other quarter-final, with the former winning 6-2 6-4 over the higher-ranked Andrey Rublev. Tiafoe won 6-4 6-4 over Alejandro Tabilo in 83 minutes for his 150th career win.