Juan Martin del Potro sped through his first-round match at the Abierto Mexicano Telcel on Tuesday. The sixth seed needed only 62 minutes to beat Germany's Mischa Zverev 6-1, 6-2.

Del Potro broke the serve-and-volleying Zverev six times out of 11 opportunities. Del Potro also won 55 per cent of his second-serve points (11/20). The Argentine will next face Spain's David Ferrer.

#NextGenATP Canadian Denis Shapovalov picked up more momentum, beating former World No. 4 Kei Nishikori, who's on the comeback from wrist surgery, 6-7(3), 6-3, 6-1. Shapovalov reached his second ATP World Tour semi-final last week at the Delray Beach Open (l. to eventual champion #NextGenATP American Tiafoe).

“I just kept fighting. I got my break, and the momentum went from there,” Shapovalov said. “It's tough to play him. He's so solid. He moves extremely well. It was an extremely difficult match for me.”

The 18-year-old Shapovalov saved nine of 10 break points, including two-of-two in the decider. The left-hander will next play third seed Dominic Thiem or British qualifier Cameron Norrie.

Reigning Next Gen ATP Finals champion Hyeon Chung had a tough first set against American Donald Young but cruised in the second 7-6(5), 6-1. Chung won 72 per cent of his first-serve points.

He will next meet 21-year-old Ernesto Escobedo of the U.S., who became the second young American in as many weeks to upset Jack Sock. Escobedo hit 12 aces and beat the fourth seed and World No. 10 7-5, 7-6(3).

Sock fell to 20-year-old countryman Reilly Opelka in three sets last week in Delray Beach. The win is Escobedo's first against a Top 10 player (1-0).

Aussie Matthew Ebden delivered the upset of the day, sending seventh seed Sam Querrey home 6-3, 1-6, 7-6(5). Querrey beat Rafael Nadal during last year's final to win the ATP World Tour 500 event. Ebden will next play Jared Donaldson of the U.S.

Watch Escobedo At Home With ATP World Tour Uncovered