Down a break in the decisive set, Grigor Dimitrov flubbed a routine return to face triple game point, swiped away a swath of clay with his toe as if trying to erase his error, and muttered to himself "that was ridiculous."

That quiet admonishment—and the electric running forehand winner he crushed out of pure frustration on the next point—helped the 12th seed clear his head and clean up his act. Dimitrov reeled off six straight games to subdue a hobbled Marcel Granollers, 6-2, 4-6, 6-2, and reach the second round of Monte Carlo.

It was a quick turnaround time for the 32nd-ranked Spaniard, who lost a three-setter to compatriot Guillermo Garcia-Lopez in the Casablanca final on Sunday, and was slowed by the collateral damage of a right thigh injury.

Lashing a backhand up the line, Dimitrov attacked in the sixth game. Granollers did well to dig out a spinning volley, but his reply sat up, and Dimitrov swooped forward and smacked a forehand pass up the line to break for 4-2. Three straight winners sealed a love hold as the Bulgarian backed up the break for 5-2.

On the ensuing changeover, Granollers took treatment for the thigh injury. Smelling salts might have been more appropriate. Flicking a backhand half-volley winner up the line, Dimitrov reached set point and closed the 33-minute opener when Granollers wailed a wild forehand wide. The world No. 14 showed his all-court skills, hitting 12 winners compared to two for his staggered opponent while reeling off 10 of the last 11 points in the set.

Trying to regroup, Granollers took a five-minute injury timeout and had his right thigh taped up. Given Granollers' precarious physical state, and the fact he could not hurt Dimitrov in forehand exchanges, the end appeared inevitable. But Granollers had other ideas.

Opening the court with a wide serve, Dimitrov could have directed his forehand anywhere, but sailed the shot wide to give Granollers the break and an unlikely 4-3 second-set lead. Serving for the set, the 28-year-old surprised Dimitrov with a serve-and-volley, finishing with a fine backhand drop volley for double set point. Dimitrov, perhaps distracted by Granollers' bluff to move forward, missed a relatively routine forehand as the owner of 10 ATP doubles titles took the second set, winning 11 of 15 trips to net.

When a rattled Dimitrov missed a short forehand up the line to face break point in the first game of the third set, the young daughter of his coach, Roger Rasheed, pushed her hands down in front of her repeatedly as if imploring their man to settle down. Attacking net, Dimitrov was in position to knock off a volley, but inexplicably hit his backhand right back at Granollers, who stood his ground and lofted a rainbow lob winner to break for 1-0.

One point from a 0-3 hole, Dimitrov regained his range and used his superior serve, movement, and forehand to take charge. He won 70 percent of the points played on Granollers' second serve and broke three times in a row to seal a two hour, one-minute victory.

The match showcased Dimitrov's dazzling strengths—he moved fluidly, he blasted his forehand virtually anywhere, and showed his subtlety with the slice backhand—as well as his shortcomings: He must learn to play the situation and score with more care and clarity. Dimitrov, who took a set from Rafael Nadal before falling in the Monte Carlo quarterfinals last year, will face Spanish qualifier Albert Ramos for a spot in the round of 16.