Fritz into Wimbledon quarter-finals after Thompson retires
The US fifth seed faced gruelling five-set battles in his opening two matches but it was a different story in his fourth-round encounter on Court One.
The Eastbourne champion broke Thompson twice to seal the first set in just 21 minutes and led 3-0 in the second set.
The Australian then had a medical time-out to deal with an apparent thigh problem.
He returned to the court and slipped 40-0 down in the fourth game before deciding he was unable to continue, with the match lasting just 41 minutes.
"He's been playing five-setters," said Fritz, 27. "He was out playing a long doubles match yesterday you know, so he's been battling out here and I respected him for coming out.
"Obviously his body's not right. So, you know, I feel bad for him."
Thompson, 44th in the rankings, was taken to five sets in his opening two singles matches at Wimbledon.
Fritz, seeking to reach his first Wimbledon semi-final, will next face Russian 17th seed Karen Khachanov, who earlier beat Kamil Majchrzak with a 6-4, 6-2, 6-3 on Court Two.
Fritz won a record fourth Eastbourne title last month and was pushed to his limits in his opening two matches at the All England Club.
The world number five rallied from the brink to defeat Giovanni Mpetshi Perricard in five sets before going the distance against Gabriel Diallo in the second round.
He then downed Alejandro Davidovich Fokina in four sets, taking his time on court over three rounds to nearly 10 hours.