Ben Shelton uses altitude to his advantage, joins Alexander Zverev in Munich quarterfinals

Alexander Zverev and Ben Shelton, the top two seeds at the BMW Open in Munich, rolled into the quarterfinals Wednesday.

World No. 3 Zverev cruised past countryman Daniel Altmaier, 6-3, 6-2, as he continued his march towards a third event crown and first since 2018. The Hamburg native broke Altmaier four times from six opportunities to advance after 80 minutes.

Zverev is seeking his first trophy since triumphing at last year’s Paris Masters. A victory Friday over Tallon Griekspoor or wild card Yannick Hanfmann would see the 27-year-old string together three wins for the first time since his run to January’s Australian Open final. Griekspoor eliminated the German No. 1 last month in his opening match at Indian Wells.

Meanwhile, Shelton remained on a championship collision course with Zverev. A day after erasing three match points to topple Borna Gojo, the second seed took a more direct approach to the finish line.

Shelton defeated two-time runner-up Botic van de Zandschulp, 7-6 (1), 6-3, claiming 83 percent of his first-serve points.

“I’ve figured out how to manage my serve, raise my first-serve percentage a bit and be winning a lot off of my first serve, I’m happy,” assessed Shelton with ATP Media after noting the higher altitude this event presents. “There’s a lot that I can continue to build on going forward in this tournament.”

The left-hander improved to 12-7 on the year in reaching his third quarterfinal. Luciano Darderi, who rallied past Miomir Kecmanovic with a 2-6, 7-6 (4), 6-4 effort, awaits.