World number two Carlos Alcaraz overcame 556th-ranked Mateus Alves of Brazil in a rain-delayed opening match Wednesday to advance to the second round of the ATP Rio Open.

Reigning Rio champion Alcaraz, who returned last week after four months out because of injury, started his title defense at the clay-court tournament Tuesday.

However, he and Alves had their match interrupted by a torrential downpour with the 19-year-old Spaniard leading 6-4, 5-3.

Home-crowd favorite Alves, 22, who had pushed Alcaraz harder than expected Tuesday, looked determined to mount a comeback when play resumed on stadium court, winning the first game.

But US Open champion Alcaraz held serve in the second to take the match, 6-4, 6-4.

Alcaraz, who made his 2023 debut last week by winning his seventh career ATP title at the Argentina Open, will next face 86th-ranked Fabio Fognini of Italy Thursday in the round of 16.

“It was a complicated match, as the final result shows,” said Alcaraz, who lost the first two games.

“Alves is a great player, which he showed here despite the conditions, having to stop and come back the next day. It’s not easy to play like that. But I’m happy with the win.”

Fognini, 35, beat Tomas Barrios of Chile in another rain-delayed match finished Wednesday, 6-2, 6-3.

“Fabio is a great player. He’s played at a very high level his whole career,” said Alcaraz.

“He’s very dangerous, with huge talent, very explosive. I’ll have to stay very focused.”

Murray ousts Zverev

Andy Murray teetered on the brink before beating Alexander Zverev in a marathon that lasted more than three hours on Wednesday to reach the quarter-finals of the Qatar Open.

Murray won 7-6 (7/5), 2-6, 7-5 after he was twice two points from defeat on his serve in the third set.

In his on-court interview after the victory, Murray said the crowd helped him.

“It makes a big difference for the players when we come and get a lot of energy and a great atmosphere from the crowd,” Murray said. “I obviously enjoyed playing in that atmosphere tonight.”

The British former World No. 1, will face French qualifier Alexandre Muller, who upset Dutch eighth seed Botic van de Zandschulp 6-2, 6-4.

Murray and Muller have never met.

“Not so familiar,” said Murray. “But he’s obviously had a good week this week coming through qualifying. He will have played four matches now, so obviously likes these conditions,”

“My coach will obviously watch video and stuff tonight to get a bit more familiar with his game, but it’s an opportunity for me in the quarters tomorrow.”

Top-seeded Andrey Rublev, the Doha winner in 2020, was in danger of suffering a fourth opening-match exit in five tournaments this year before fighting his way back from 2-5 in the third set to edge Dutchman Tallon Griekspoor 1-6, 6-1, 7-6 (8/6).

Griekspoor squandered three match points on his serve in the ninth game of the third set.

He then saved two match points in the tie-break before Rublev won in one hour 54 minutes.

Rublev will face Jiri Lehecka, a 21-year-old Czech, who beat Finn Emil Ruusuvuori, 6-2, 7-6 (7-2).

Canadian second seed Felix Auger-Aliassime struggled against Jason Kubler’s serve in the first set but recovered to overcome the Australian 4-6, 6-1, 6-4 after two hours and 16 minutes.

Kubler had won the only previous meeting in Newport last year.