Richard Gasquet converted all six of his break points as he beat Nicolas Almagro 6-4 6-0, while Milos Raonic had 13 aces in a 6-3 7-5 win against wild card Marco Cecchinato in the first round of the Monte Carlo Masters.
Raonic broke in the 11th game of the second set on Monday and quickly moved 40-0 up as he served for the match.
Cecchinato saved two match points before the Italian sent a high backhand wide on the next point.
“I let myself fall into a little bit too much of a defensive pattern where I was playing a little too far back,” Raonic said.
“It didn’t allow me to use my game to dictate. I was a little bit more reactive rather than proactive.”
Although his big-serving game is more effective on quicker surfaces, the 10th-seeded Canadian thinks the slower clay still suits his game.
“It gives me time,” said Raonic.
Raonic will play either Spaniard Daniel Gimeno-Traver or Uruguayan Pablo Cuevas in the second round.
Austria’s Dominic Thiem overcame a difficult first set, where he dropped his serve twice, to beat qualifier Jan-Lennard Struff of Germany 1-6 6-3 6-4.
Gael Monfils, a semi-finalist last year and seeded 13th, also advanced, beating Gilles Muller of Luxembourg 7-5 6-0.
France’s Benoit Paire rallied to beat Spaniard Inigo Cervantes 4-6 6-2 7-6 (8-6); Roberto Bautista Agut defeated Albert Ramos-Vinolas 6-4 7-6 (7-4) in an all-Spanish match and Bulgarian Grigor Dimitrov beat qualifier Filip Krajinovic 6-3 6-2.
British player Aljaz Bedene had eight aces in a 6-2 6-3 win against Czech Lukas Rosol and next faces fifth-seeded Rafael Nadal of Spain, who won the last of his eight straight titles here in 2012.
Alexander Zverev eased past Russian Andrey Rublev 6-1 6-3 in a match of two 18-year-olds and he next plays No.7 David Ferrer, the 2011 runner-up.
There were also wins for Spaniards Guillermo Garcia-Lopez and Pablo Carreno Busta and Frenchman Pierre-Hugues Herbert.
No.2 Andy Murray and No.3 Roger Federer are in second-round action on Tuesday.
Murray faces Herbert and Federer, who is returning from more than two months out following surgery on his left knee, takes on Garcia-Lopez.
Top-ranked Novak Djokovic begins his title defence on Wednesday against either Gabashvili or Czech Jiri Vesely, who play on Tuesday.