Alexander Zverev shocked in Acapulco opener by Daniel Altmaier as Holger Rune wins on Patrick Mouratoglou return

Top seed Alexander Zverev suffered a surprise defeat to Daniel Altmaier in his opening match at the Mexican Open.

Zverev, who won the tournament in 2021, was beaten 6-3 3-6 6-3 by the world No. 57.

Altmaier had lost his previous four matches in a row but saved six of seven break points to beat his fellow German, including three in the deciding set.

Second seed Holger Rune had no troubles winning his opener as he beat Michael Mmoh 6-2 6-3.

It was Rune’s first match since reuniting with coach Patrick Mouratoglou.

“We might both agree that I executed [the game plan] very well. It just feels good.

“I’m just trying to build on every match. I thought it’s a great start, because it’s a very strong field in Acapulco, so you’ll have to play great tennis to be able to go deep and potentially win the tournament.”

Rune next faces American qualifier Aleksandar Kovacevic, who beat Los Cabos champion Jordan Thompson 6-3 5-7 6-4.

There were also wins for fourth seed Casper Ruud and sixth seed Frances Tiafoe.

Los Cabos runner-up Ruud won 6-4 6-7(5) 6-3 against Christopher Eubanks while Tiafoe overcame Max Purcell 4-6 6-3 6-0.

Stefanos Tsitsipas looks set for a return to the top 10 after he won 6-3 6-4 against Roman Safiullin.

Tsitsipas is currently up from No. 12 to No. 10 in the live rankings and could move higher with a deep run in Acapulco.

Reflecting on his win over Safiullin, he said: “It’s one of those first rounds that you get good opponents and a very good, strong start from the beginning of the tournament.

“I knew that dealing with Roman, he’s someone that can play good on these kinds of surfaces. He takes the ball early, pushes you back. That was the main thing I had to deal with today, which I did pretty well.”

Tsitsipas will next play Italian qualifier Flavio Cobolli, who stunned Felix Auger-Aliassime 2-6 6-3 6-2 in the first round.