Alexander Zverev hits a return to Rafael Nadal during their semifinal match at the Rolex Paris Masters on Saturday in Paris, France. Photo: VCG

Top seed Rafael Nadal's bid for a maiden Paris Masters title was halted on Saturday when the Spaniard was beaten 6-4, 7-5 in the semifinals by German fourth seed Alexander Zverev.

Nadal, who reached the final at Bercy in 2007, was only briefly in contention as he surrendered his serve three times.

The 20-time Grand Slam champion broke back after falling 4-2 behind in the second set but it was a brief comeback as the 23-year-old Zverev stole his serve again in the 11th game.

He then served it out, prevailing on his second match point when Nadal's forehand flew wide.

Zverev will look to claim his fourth Masters title against Russian third seed Daniil Medvedev, who qualified with a commanding 6-4, 7-6 (7/4) victory against Canadian Milos Raonic.

"I feel good. Look, I'm in the final of a Masters, so I'm quite happy about that. And I have just beaten Rafa," said Zverev.

"So that is never easy to do. I think the whole world will agree with me on that, all the players will agree with me on that. It's going to be a final against Daniil. Obviously two best players of the tournament are still left."

Nadal said he was satisfied with his overall performance in Paris, although he rued his tactical game plan.

"I did things well. I think I returned better than the other days, but was impossible at the beginning. I think I understood that I had to go back too late, because I was not able to, he was serving bombs and hitting the right spots all the time," he said.

"So I decided to go, like, eight meters behind the baseline later on in the match and I think worked better for me.

"It has been a positive tournament for me. Of course not happy about the loss, but that's part of the game. 

"I spent hours on court. Of course I wanted to win the tournament, but it's always difficult."

Medvedev hit 31 winners to 12 unforced errors in a muffled atmosphere at the Bercy arena, where the tournament is being played without spectators amid government restrictions to contain the rise of COVID-19 cases in France.

The 24-year-old, who arrived in Paris having lost five of his eight previous matches, broke for 3-2 as Raonic made yet another forehand unforced error.

Both then stayed strong on serve and Medvedev, who saved six of seven break points throughout, bagged the opening set with a timely serve and volley on his first opportunity.

Raonic dropped serve in the 11th game of the second set but he broke straight back to force a tiebreak, in which he was out of sorts, with Medvedev wrapping it up with a smash to reach his fourth Masters final.

"When you play against Milos, you are always at risk because [if] one time he breaks you, it is very tough to break him back," said Medvedev.

"It was shaky here and there, but I am really happy to be through to the final."