WORLD number two Alexander Zverev‘s post-Australian Open disaster run continued in Acapulco with a shock straight sets loss to talented young American Learner Tien. Zverev – who opted for the easier route compared to many of his Top 10 counterparts since Melbourne Park – boasts a mediocre 4-3 win-loss record across his past three tournaments heading into the Sunshine Swing.

On a disastrous day for Acapulco organisers as the top five seeds were all eliminated – two by choice – Zverev’s frustrating build-up in a bid to win Roland Garros after another near miss in Australia rolled on. The German has been top seed in all three tournaments but failed to reach the final four in any, having lost in Buenos Aires and Rio on clay by the quarter finals stage, before his Round of 16 exit on the Mexican hardcourts.

The left-handed American pulled out all the stops to defend the German brilliantly, and force the world number two to overplay. Zverev hit 34 unforced errors to just 24 winners, with Tien able to to win 67 per cent of the German’s second serve points, while maintaining 61 per cent of his own second serve points. He broke three times to one during the regulation 6-3 6-4 triumph.

Incredibly, Zverev’s sole break came early in the second set to race to a 4-1 lead and be on the verge of sending the match to a decider. However, an unflustered Tien racked up five consecutive games to seal the match in one hour and 28 minutes.

“I just went out there and tried to control my side of the court,” Tien said post-match. “Obviously I knew it was going to be a tough match. To come through feels great… I think just focussing on what I can control and keeping my cool as best as I can has really taken me a long way.”

Along with his victory, the American broke some records including becoming the youngest United States male to defeat a top three opponent in 24 years, and crack through for his second Tour quarter final. He is also up to 68th on the live world rankings.

Tien takes on Czech Tomas Machac, who all of a sudden has become the highest ranked player remaining in the tournament. Machac defeated German wildcard Daniel Altmaier, 7-6 6-1. It was a dirty day for seeds in general with second and third seeds Casper Ruud and Tommy Paul both withdrawing pre-match, Holger Rune lasting three games in his loss to Brandon Nakashima, and then Ben Shelton (fifth seed) bowing out as well.