Monfils a surprise loser at Croatia Open

Second-seed Gael Monfils has been bundled out of the Croatia Open after three-sets loss to Brazilian Rogerio Dutra Silva in the round of 16.

After a first-round bye France's Gael Monfils was knocked out in his second round encounter. (AAP)

Rogerio Dutra Silva has upset second-seeded Gael Monfils in three sets to reach the quarter-finals of the Croatia Open on Thursday.

The 64th-ranked Brazilian accounted for the Frenchman 7-6 (7-5) 4-6 6-3 to set up a last-eight meeting with Alessandro Giannessi, after the Italian beat qualifier Kenny De Schepper of France 6-2 3-6 6-3.

Defending champion Fabio Fognini, the third seed, overcame a second-set wobble to defeat unseeded Nicolas Kicker of Argentina 6-4 1-6 6-2.

In the quarter-finals, Fognini will play lucky loser entry Andrey Rublev.

The Russian beat last year's finalist Andrej Martin of Slovakia 7-6 (7-5) 7-5.