Gael Monfils maintained his perfect record against Marin Cilic to reach the second round and Daniil Medvedev suffered a shock defeat at the Dubai Tennis Championships on Tuesday.

Cilic's return from a knee injury did not go to plan as the mercurial Monfils consigned the third seed to a 6-3 4-6 6-0 defeat, making it four wins out of four against the Croatian.

Monfils, on a high after beating Stan Wawrinka in Rotterdam to claim the eighth ATP title of his career, broke the 2014 US Open champion five times to move into the second round.

Cilic, playing only his second tournament of the year after a fourth-round Australian Open exit, served just the one ace and could only manufacture a solitary break-point opportunity in a rusty performance.

The former world number three was blown away in the second set, the unseeded Monfils not losing a single point on serve as he sealed a meeting with Marcos Baghdatis.

Medvedev has had an impressive season to date, but the eighth seed from Russia went down 6-3 6-3 to qualifier Ricardas Berankis.

The 113-ranked Berankis claimed his first victory since winning a Challenger Tour event in Rennes last month, breaking twice in each set to pull off an upset.

Top seed Kei Nishikori, making his debut in the tournament, eased past Benoit Paire 6-4 6-3, while Stefanos Tsitsipas was made to work for a 6-4 3-6 6-3 victory over Matthew Ebden two days after winning his first title of the season in Marseille.

Tomas Berdych came through a three-setter with lucky loser Ilya Ivashka, while Borna Coric, Egor Gerasimov, Denis Kudla and Hubert Hurkacz also advanced.