Dominic Thiem surged to an emphatic victory on his return to the ATP Tour at the Madrid Open.

US Open champion and two-time Madrid Open runner-up Thiem was playing his first match in nearly two months on Tuesday, having taken a break to recharge.

But it did not take him long to get back into the groove, the third seed easing through his second-round match with American qualifier Marcos Giron 6-1 6-3 at the ATP 1000 event.

"I was uncertain how things will be going. The game worked out very well in the past days of practice, but I was always practising on the outside courts which are faster, which are smaller, so I was just not sure how it was going to be in the match," Thiem said.

"But there were some things which I think made [the match] a little bit easier after such a long time, especially the conditions in Madrid, which are great for me.

"Then [I have] amazing memories on this court, where I already played probably some of the best matches of my career. I think that's why things worked out quite well tonight."

Next for Thiem in the last 16 is Alex de Minaur, who was leading 6-2 3-0 when Lloyd Harris retired from their match.

It was a largely strong day for the seeded players in the Spanish capital, home hope and ninth seed Roberto Bautista Agut beating Marco Cecchinato 6-2 6-7 (3-7) 7-5 in a first-round clash.

Andrey Rublev – the sixth seed – came from a set down to beat Tommy Paul 6-7 (5-7) 6-3 6-4 and eighth-seeded Italian Matteo Berrettini joins him in the last 16 after defeating compatriot Fabio Fognini 6-3 6-4.

Jannik Sinner, who is seeded 14th, won in the first round after Guido Pella retired in the second set. However, four seeds did tumble out of the draw.

Felix Auger-Aliassime was thrashed 6-1 6-4 by Casper Ruud in the first round and his Canadian compatriot Denis Shapovalov was beaten 6-4 5-7 6-4 by Alexander Bublik in their second-round encounter.

Miami champion Hubert Hurkacz suffered a second successive second-round exit, the 12th seed defeated 5-7 7-6 (9-7) 6-3 by John Millman in a match that went the distance having lost at the same stage in Monte Carlo.