'What on earth': Tennis world baffled by shock Daniil Medvedev act

Daniil Medvedev was in a particularly volatile mood on Wednesday as he crashed out of the World Tennis Tournament in Rotterdam at the first hurdle.

The Russian star became the latest high-profile first round casualty after losing in straight sets to Dusan Lajovic, squandering his chance of taking Rafael Nadal's place as World No.2.

'DARK PLACE': Aussie star reveals battle with depression

'NOT HUMAN': Tennis world erupts over Alex de Minaur moment

The World No.3 was the top seed for this week's tournament following his run to the Australian Open final, but was dumped out 7-6 (7/4), 6-4 in just over 90 minutes.

Medvedev smashed his racquet after being broken in the ninth game of the second set, having a row with the umpire and starting the final game with a point penalty as a result.

But it was an extraordinary moment earlier in the second set that left fans and commentators baffled.

At 1-1, Medvedev inexplicably turned his back mid-point as Lajovic was about to return the ball.

The Russian appeared to completely give up on the point, but got incredibly lucky when Lajovic dumped his backhand into the net.

“What on earth is going on there,” one commentator said on Tennis TV.

Fans were equally as stunned.

Medvedev joins Zverev as first-round casualty

The defeat was particularly painful for Medvedev as he would have replaced Nadal as World No.2 had he reached the final.

Nadal withdrew from Rotterdam with a back injury.

"I think I was very focused the whole match and not influenced by his good serves and shots," said Lajovic.

"I knew if I stayed in the match, I'd get my opportunities and change the rhythm."

Medvedev joins World No.7 Alexander Zverev and three-time grand slam winner Stan Wawrinka in exiting the tournament early.

Zverev, 23, was dumped out by Kazakhstan's Alexander Bublik on Wednesday in a shock straight sets 7-5, 6-3 defeat.

Zverev was seeded third in the tournament but was surprised by 43rd-ranked Bublik in just one hour, 19 minutes.

Bublik, who reached the final of last week's tournament in Singapore, will face Tommy Paul in the second round after the American defeated Italy's Lorenzo Sonego 6-4, 7-6 (9/7).

"Beating Sascha is great," Bublik, who has now won his past three matches against top-10 opponents, said after the match.

"There were ups and downs for both of us throughout the match, I got a bit lucky and I was perhaps a little more consistent.

"I'm just enjoying playing matches right now."

with AFP

Click here to sign up to our newsletter for all the latest and breaking stories from Australia and around the world.