No. 2 seed Andrey Rublev of Russia fell behind 5-2 in the opening set before storming back for a 7-5, 6-2 triumph over Serbia's Filip Krajinovic in the first round of the Dubai Duty Free Tennis Championships on Monday in the United Arab Emirates.

Krajinovic broke Rublev's serve in his first service game to help build the early advantage, but Rublev won the final five games of the set before cruising in the second, winning 26 of 29 first-service points (89.7 per cent) and converting four of six break-point opportunities.

No. 7 seed Alexander Zverev of Germany rallied to beat Czech opponent Jiri Lehecka 4-6, 6-3, 6-4.

Alejandro Davidovich Fokina of Spain, Tallon Griekspoor of the Netherlands, wild card Thanasi Kokkinakis of Australia, Lorenzo Sonego of Italy and Russian qualifier Pavel Kotov also won their opening matches.

Movistar Chile Open

Argentine qualifier Juan Manuel Cerundolo upset No. 7 seed and fellow countryman Pedro Cachin 6-4, 3-6, 6-3 in the first round of the clay-court tournament in Santiago.

Cerundolo coped with Cachin's nine aces by winning 39 of his 46 first-service points (84.8 per cent).

Defending champion Pedro Martinez of Spain also bowed out early, as German qualifier Yannick Hanfmann handled business in their match 6-2, 6-0. Chile's Alejandro Tabilo pulled out a 6-0, 6-7 (4), 7-6 (5) win over Spain's Jaume Munar for the right to face top-seeded Lorenzo Musetti of Italy in the second round.

Abierto Mexicano Telcel

The three seeded U.S. players in action all won their opening-round matches in Acapulco, Mexico.

Third-seeded Taylor Fritz outlasted U.S. countryman John Isner 3-6, 6-3, 6-4. Sixth-seeded Frances Tiafoe downed Japan's Yoshihito Nishioka 7-6 (6), 6-4, finishing with a 9-2 edge in aces. Seventh-seeded Tommy Paul closed out Ecuador's Emilio Gomez 6-1, 7-6 (4).

In another all-U.S. matchup, Michael Mmoh prevailed 7-6 (3), 6-1 over Marcos Giron. Fourth-seeded Holger Rune of Denmark rallied past the United States' Ben Shelton 6-7 (7), 6-4, 6-2, and Canada's Denis Shapovalov came from behind to defeat Serbia's Miomir Kecmanovic 6-7 (4), 6-0, 7-5.

In the final match of the night, second-seeded Casper Ruud of Norway staved off Argentine qualifier Guido Andreozzi 6-4, 4-6, 7-6 (2). Also advancing to the second round were Spain's Feliciano Lopez and Japan's Taro Daniel.

-Field Level Media