Jared Donaldson will face Rafael Nadal in the second round of the Shanghai Masters after coming from a set down to beat Pablo Cuevas on the eve of his 21st birthday.
Donaldson recovered from losing a first-set tie-break to win 6-7 (7-9) 6-4 6-4 on the opening day of the tournament.
The American gave himself an early birthday present by setting up a first meeting with world number one Nadal, who beat Nick Krygios to win the China Open on Sunday.
Donaldson fired down 14 aces and saved all eight break points he faced, securing one break in the second set and a decisive one in the third to prevail.
Lucas Pouille, the only seed in action, saw off Daniil Medvedev 6-4 6-2 to reach round two.
Fabio Fognini will be Pouille's next opponent after the Italian got the better of Fernando Verdasco 2-6 6-4 6-2.
Gilles Simon will come up against the in-form David Goffin, riding on the crest of a wave following back-to-back tournament wins in Tokyo and Shenzhen, following the Frenchman's 6-3 6-4 triumph over wildcard Wu Yibing.