Roger Federer eased through his French Open return with a straight-set win over Uzbekistan's Denis Istomin.

The 39-year-old Swiss played smoothly and confidently as he won 6-2 6-4 6-3.

Meanwhile, Russian second seed Daniil Medvedev ended his misery at Roland Garros as he beat Alexander Bublik for his first win on the Paris clay.

Medvedev, 25, won 6-3 6-3 7-5 against Kazakhstan's Bublik, ending a run of four successive defeats in round one.

The two-time Grand Slam finalist broke out into a relieved grin after serving out for victory in under two hours.

"I felt I was not playing well in the past here, but this time I feel comfortable," Medvedev said.

"I am running well and moving well. I want to keep playing at this level."

Medevdev has rarely concealed his dislike for the red dirt, having earned just 11 of his 179 career wins on the surface going into Roland Garros.

He had earned only one clay-court victory - against Spain's Alejandro Davidovich Fokina in Madrid - this year.

Despite calling it the "worst surface ever" at the recent Italian Open, Medvedev said in his pre-Grand Slam news conference that practice in Paris had been "amazing" and that the conditions helped him play like he does on hard courts.

That showed in a dominant performance against Bublik, where the hotter and faster conditions seemed to suit his game.

Medvedev is seeded second at Roland Garros - one above 13-time champion Rafael Nadal - because the seedings are based on world rankings, meaning the Russian finds himself in the opposite side of the men's draw to Nadal, top seed Novak Djokovic and Federer.

There are no Grand Slam champions in his half following US Open winner Dominic Thiem's defeat on Sunday.

Greek fifth seed Stefanos Tsitsipas and German sixth seed Alexander Zverev - who are both strongly tipped to go far - remain in there after winning their opening matches.