Monte Carlo - Switzerland's Stan Wawrinka kicked off the defence of his Monte Carlo Masters title on Wednesday with a 6-1, 6-4 defeat of Argentine Juan Monaco to progress to the third round.
The seventh seed who lifted his first elite Masters 1000 title here a year ago as he beat compatriot Roger Federer for the title, spent 71 minutes in getting past Monaco.
"I played well, and I'm pleased to be back on clay." said the winner, who broke five times from 14 chances. "It's nice to be defending a title and starting it out like this."
Wawrinka, the 2014 Australian Open winner, will await an opponent from ninth seed Grigor Dimitrov and Italian Fabio Fognini.
The Swiss comes onto the spring clay with a 17-4 match record and titles in Chennai and Rotterdam.
The 30-year-old successfully defended a title for the first time in January, winning Chennai for the second year in a row.
Spanish 16th seed Tommy Robredo crushed compatriot Marcel Granollers 6-1, 6-1 in an early match played under the first clouds of the week at this Mediterranean principality.
Second seed Federer was beginning later against Frenchman Jeremy Chardy while eight-time champion Rafael Nadal was putting two weeks of clay training to the test in a second-round match against French wild card Lucas Pouille.
Results on the fourth day of the Monte Carlo Masters on Wednesday (x denotes seeded player):
Stan Wawrinka (SUI x7) bt Juan Monaco (ARG) 6-1, 6-4
Tommy Robredo (ESP x16) bt Marcel Granollers (ESP) 6-1, 6-1
Rafael Nadal (ESP x3) bt Lucas Pouille (FRA) 6-2, 6-1
Tomas Berdych (CZE x6) bt Sergiy Stakhovsky (UKR) 6-4, 7-6 (7/2)
Roberto Bautista Agut (ESP x12) bt Philipp Kohlschreiber (GER) 6-7 (3/7), 6-3, 7-6 (7/4)
Grigor Dimitrov (BUL x9) bt Fabio Fognini (ITA) 6-3, 6-4
Gilles Simon (FRA x10) bt Benoit Paire (FRA) 6-4, 7-5
Roger Federer (SUI x2) bt Jeremy Chardy (FRA) 6-2, 6-1
Milos Raonic (CAN x4) bt Joao Sousa (POR) 6-3, 7-6 (7/4)
John Isner (USA x15) bt Viktor Troicki (SRB) 7-6 (7/4), 7-6 (7/5)
Jo-Wilfried Tsonga (FRA x11) bt David Goffin (BEL) 6-3, 6-4