The No. 7 seed Canadian conceded only one point on his first serve and had 11 aces. Shapovalov, who lost in the semifinals four years ago, will next take on Japanese qualifier Rio Noguchi for a place in the quarterfinals.
“[This was] definitely one of my best serving matches,” Shapovalov said. “I kind of felt like I needed to against Steve … I’m very happy with my serving performance today and hopefully I can keep it up throughout the week.”
Fritz won 6-2, 6-7 (2), 6-1 to set up a tie with Hiroki Moriya.