The American saved a pair of match points in a wild sequence in his third-set tiebreak with Dan Evans.
Tommy Paul led Martin Damm 6-4, 1-2 when he rolled his left ankle forcing him to retire from the Miami Open.
"We're strong women. She proved it. I proved it," Paula Badosa said after losing to best friend Aryna Sabalenka in her first match since the death of her ex-boyfriend.
The former World No.4 plans to hit the clay next.
Taylor Fritz serves up spice in his partnership with Maestro Dobel.
The Heat is oppressive in Miami, even with temperatures below 80.
Photographer Matthew Calvis is roaming the grounds of the Miami Open and shares day three shots from Hard Rock Stadium.
