The top-ranked Nadal needed only 75 minutes to get past the ninth-ranked Frenchman, who was broken four times.
“The truth is it was a pretty complete game,” said Nadal, who is 29-1 at the clay court tournament, which he is bidding to win for a sixth time. “I'm very happy since this is a matchup between two of the best players in the world and to win 6-2, 6-2 makes me very happy.” Nadal rallied from 40-0 down in the third game to convert his first break point with a forehand winner, with Monfils pushed deep behind the baseline.
Nadal extended his lead to 4-1 when Monfils netted a backhand to be broken again, and Nadal held serve to take the first set.
The second set was a near replica of the first as Nadal broke Monfils in the third and fifth games again.
Monfils hit wide to trail 2-1 and then sent a forehand long after a net exchange to be broken for the fourth time.
Nadal held serve to close out the match and set up a match against Ivan Dodig of Croatia, who outlasted Spanish player Feliciano Lopez 6-4, 2-6, 6-4.
“This is super positive,” said Nadal, the who is coming off his seventh straight Monte Carlos Masters title and improved to 30-0 on clay since 2010. “But there's still much to achieve.” Ferrer, who lost to Nadal in the Monte Carlo final on Sunday, moved a step closer to his fourth title match of the year by dismissing Jurgen Melzer 6-3, 6-3.
Melzer slammed his racket into the red dirt after netting to set up set point for Ferrer, who converted it when the Austrian sent a shot long.
Melzer's frustration carried over into the second set as he slapped a backhand wide to be broken in the first game.
But Melzer —who beat Roger Federer in Monte Carlo — broke back to even it at 1-1.
Ferrer needed treatment on his left calf but shrugged off the twinge to reach his fifth semifinal of the season after breaking for 4-3. The sixth-ranked Ferrer sealed the victory when Melzer hit long.
Nicolas Almagro — who will reach a career-high 10th when the rankings are released on Monday — beat Juan Carlos Ferrero 6-3, 6-3 to set up the all-Spanish semifinal with Ferrer, who leads their head-to-head record 6-0.
