Dominic Thiem has yet to win on the ATP Tour since his return in April as he lost in the first round of the French Open ©Getty Images

Two-time French Open finalist Dominic Thiem of Austria insists it will "take time" for him to return to the top of his game after suffering a "painful" first-round defeat to Bolivian Hugo Dellien.

Thiem reached the final in 2018 and 2019 but fell at the first hurdle on this occasion after suffering a comprehensive 6-3, 6-2, 6-4 defeat to the world number 87.

The 2020 US Open champion was playing in just his sixth match of 2022 since returning from a wrist injury sustained last June.

He has yet to register a win since he came back on the Association of Tennis Professionals Tour in April having missed nine months of action.

But Thiem, whose last win came a year ago at the Italian Open, stressed that patience will be key in his comeback.

"I have to accept it and even though it was [a] really painful defeat now, week after week, it's still nothing unexpected happened," said Thiem, who reached a career-high ranking of world number three in 2020.

Olympic champion Alexander Zverev was in superb form in his first round encoutner in Paris ©Getty Images
Olympic champion Alexander Zverev was in superb form in his first round encoutner in Paris ©Getty Images

"If I would have won many matches or whatever, would have been a big surprise.

"So it's painful, I'm very disappointed, but it goes on.

"[There are] zero physical issues.

"I also have no mental problems with the forehand, I'm not scared or anything, but the problem is that, practise was really decent already with the forehand but then [the] match situation is something different.

"I'm obviously a little bit more tight, more nervous and obviously the whole body gets more tight, gets more nervous and right now that's toxic to my forehand because I'm still missing the fine feeling there, I'm missing it a lot."

Canada’s Felix Auger-Aliassime survived an almighty scare as he battled back from two sets down for the first time in his career to reach the second round in Paris.

The world number nine recovered from a slow start to beat Peruvian qualifier Juan Pablo Varillas 2-6, 2-6, 6-1, 6-3, 6-3.

There were no such issues for Spanish star Carlos Alcaraz and third seed Alexander Zverev who both triumphed in straight sets.

Alcaraz thumped lucky loser Juan Ignacio Londero of Argentina 6-4, 6-2, 6-0, while Olympic champion Zverev impressed in a 6-2, 6-4, 6-4 victory over Austrian qualifier Sebastian Ofner.

"I had a very stable clay-court season," said Zverev.

"Semis in Monte Carlo, final in Madrid, semis in Rome.

"But I didn’t win any tournaments. 

"I’m always somebody that likes to win, rather than be stable.

"I’d rather lose first round, first round, first round and then win a tournament, so hopefully I can do that here. 

"Hopefully I can play my best tennis here."

Davidovich Fokina of Spain put together a superb run to reach the Monte-Carlos Masters final last month but crashed out in the first round of the French Open.

The Spaniard won the first set only to lose 2-6, 6-0, 6-4, 6-2 to Tallon Griekspoor of The Netherlands.

Grigor Dimitrov of Bulgaria thrashed Marcos Giron of the United States 6-1, 6-1, 6-1, while Pablo Cuevas of Uruguay defeated American 31st seed Jenson Brooksby 6-2, 6-1, 6-1 in another one-sided encounter.

There were also straight sets wins for Fabio Fognini of Italy, Bernabé Zapata Miralles of Spain and Australian Jason Kubler.