PARIS, FRANCE (AFP) — Carlos Alcaraz slipped to a shock defeat on his return from injury on Tuesday in the Paris Masters while Alexander Zverev needed three sets to see off Marton Fucsovics.

Spanish world No. 2 Alcaraz, who was making his return to the court following injuries to his lower back and left foot, had been given a bye in the first round but had no answer to Russian qualifier Roman Safiullin who eased through 6-3, 6-4.

"He didn't surprise me at all because I knew that he has been playing at a great level these last few months, beating big guys, reaching finals," said a disconsolate Alcaraz.

"I knew that he was going to play at a high level."

Safiullin, ranked 45 in the world, cancelled out an early Alcaraz break in the first set and then never looked back as he ran on to claim the opener 6-3.

The same scenario then played out in the second set, with Alcaraz breaking for an early lead only for his opponent to strike back immediately.

Having only announced he would play in the tournament last Wednesday, Alcaraz looked far from his sharpest.

"I just didn't feel well, you know, on the court," he said.

"A lot of things to improve, a lot of things to practice."

"I think I didn't move well. In the shots, I think I had a good quality of shots. But physically, in terms of movement, I have to improve a lot."

However, much credit must go to Safiullin, who was relentless in getting over the line for a career-boosting win in what was his first meeting with the Spaniard.

The 26-year-old held his nerve under pressure from the Wimbledon champion to serve out for the win, despite facing several deuce points in the final game.

"Even if he's not in the best shape it's tough to beat him," Safiullin said.