Denis Shapovalov fought off one match level and beat American Marcos Giron 6-7 (3), 6-0, 7-6 (4) within the first spherical of the Swiss Indoors on Tuesday.
The Canadian, seeded ninth, had misplaced three of 4 profession matches in opposition to Giron coming into the match in Basel.
Shapovalov, with serve, fought off the match level whereas trailing 30-40, 5-6. He then dominated the tiebreaker to take the match in opposition to the world No. 57.
Shapovalov out-aced Giron 13-3 and saved 5 of seven break factors.
The Richmond Hill, Ont. product is coming off a run to the semifinals on the Stockholm Open.
Shapovalov will subsequent face fortunate loser Valentin Royer of France.
Felix Auger-Aliassime meets Gabriel Diallo in an all-Montreal first-round matchup on Wednesday.