Third seed Federer cruised past ninth seed Juan Martin Del Potro 6-3 6-2 for his 250th win in ATP Masters events, while world number two Nadal was forced to battle for a 4-6 7-5 6-4 victory over David Nalbandian.
Del Potro seemed like he might prove a significant obstacle to Federer when he created two break points in the opening game of the match.
But the Swiss saved them both and was dominant from that point on.
Federer looked forward to renewing his rivalry with Nadal, telling www.bnpparibasopen.com: "He's got a great work ethic, and obviously he's one of the great players of all time.
"I have had some great matches with him all around the world by now."
Nadal had life much tougher as he dropped his first set of the tournament against Nalbandian, but kept his composure to advance.
Nadal has won 18 of his previous 27 matches with Federer.
Nadal said on www.atpworldtour.com: "They're always special matches, especially because they're always are in very important matches for both of us.
"That always makes the match very special. But even if it's not the final, being in the semi-finals is an important match.
"Playing against Roger always means a little bit more than against the rest of the opponents because I am playing probably against the best of the history, and because I played probably the most important matches of my career against him and probably him against me."
In the women's draw, world number one Victoria Azarenka extended her winning streak at the start of 2012 to 22 matches as she beat 18th seed Angelique Kerber 6-4 6-3.
Azarenka's run is the best start to a season in the women's game since Martina Hingis won her first 37 games in 1997.
Azarenka, though, was generous in her praise for her German opponent.
"I'm really impressed by the way Angelique was playing," Azarenka said on www.wtatour.com. "It was the first time we played on the pro tour, so it was a little bit new for me, and she showed some excellent tennis.
"I think she's a great player and she really pushed me to raise my level and really dig to win that match."
Azarenka will face second seed Maria Sharapova, who was 6-4 0-1 up when opponent Ana Ivanovic was forced to withdraw with what appeared to be a back injury.