Andreev was twice a break up in the deciding set but couldn’t finished off fourth-seeded Cilic, who hasn’t lost much so far this year.
Following a first-round bye, Cilic improved his win-loss record to 21-4, second on tour only to Andy Roddick. They and Juan Carlos Ferrero are the only players to have won two titles this season.
Cilic, into the Monte Carlo third round for the first time, next plays either Andreas Seppi of Italy or Albert Montanes of Spain.
No. 5 Jo-Wilfried Tsonga of France also reached the third round after beating Nicolas Almagro of Spain 7-6 (5), 7-5. The score was no surprise— Tsonga was pushed by Almagro at the Australian Open to win 9-7 in the fifth set.
Two unforced errors from Almagro gave the Frenchman an opportunity to serve for the match at 5-3—but he wasted it with sloppy strokes.
Almagro had Tsonga in trouble on his serve throughout the match, double-faulting three times, but Almagro converted only one of his 11 chances to break Tsonga in his Monte Carlo debut.
“It was not an easy draw for my first match on clay; he’s an excellent player,” Tsonga said. “I played solid. I had a good forehand, good backhand. I was able to stop him from being too aggressive against me.”
Tsonga will play two-time former Monte Carlo champion Ferrero or Benjamin Becker of Germany in the third round.
“I never played on clay against him, but I know that on hard courts he’s a tough player,” Tsonga said of Ferrero. “It’s hard to stop him. He makes you run right and left a lot. I can imagine what it’s going to be like on clay.”
No. 6 Fernando Verdasco of Spain had a far easier win, beating Frenchman Julien Benneteau 6-2, 6-1.
“He just put the ball where he wanted and he was always a step ahead of me,” Benneteau said of Verdasco.
“I didn’t make unbelievable winners, but I played very solid. I didn’t make unforced errors,” Verdasco said. “Maybe (Benneteau) was a little bit tired from yesterday. He had a three-set match yesterday and it was my first match today.”
Verdasco next faces No. 10 Tomas Berdych of the Czech Republic, who thrashed Richard Gasquet of France 6-2, 6-0.
Berdych dominated from the start, breaking Gasquet’s first service game and five times overall.
Berdych was rarely troubled and saved the three break points he faced. He clinched victory when he returned Gasquet’s weak serve with a forehand pass that the Frenchman could not reach.
In remaining first-round matches, No. 12 Tommy Robredo of Spain, No. 13 Stanislas Wawrinka of Switzerland, and No. 15 Jurgen Melzer of Austria all won in straight sets.
Melzer beat Paul-Henri Mathieu of France 6-3, 6-2; Robredo beat Horacio Zeballos of Argentina 6-3, 6-3, and Wawrinka won 6-2, 6-4 against Romania’s Victor Hanescu.
Thiemo de Bakker of the Netherlands beat Eduardo Schwank of Argentina 6-3, 7-5 to set up a match against five-time defending champion Rafael Nadal of Spain on Wednesday, when top-seeded Novak Djokovic also plays.
Montanes beat No. 16 Marcos Baghdatis of Cyprus 6-4, 6-2.
Viktor Troicki of Serbia and French players Michael Llodra and Florent Serra all advanced to the second round.
