Zverev suffers shocking first-round exit at Mexican Open

Top seed Alexander Zverev was stunned by German compatriot Daniel Altmaier and suffered a first-round exit at the Mexican Open, reported dpa.

Zverev was defeated 3-6, 6-3, 3-6 on Tuesday evening. Altmaier advanced to the last 16 and will face Serbia's Miomir Kecmanovic.

"I think winning against a German is something special. He's the number one in our country, has achieved so much for the nation," Altmaier said.

That was his fourth win against a top 10 player, while Zverev was defeated by a German player for the first time in almost five years.

Olympic champion Zverev missed out on a place in the final of the ATP tournament in Los Cabos last week, after recently returning from an illness.

He helped Germany win the mixed team United Cup last month and was looking for his first individual title of the year.