Federer delivers crushing victory over Stepanek
Swiss Roger Federer hits a return to Czech Radek Stepanek during the Monte-Carlo ATP Masters Series Tournament tennis match in Monaco on April 16, 2014 - by Valery Hache
Federer's rout in 52 minutes was seven minutes longer than another easy victory by holder Novak Djokovic a day earlier.
"I was able to get a lot of returns back into play," said Federer. "On clay, when you have the upper hand from the baseline, it's kind of hard to get out of it.
"I think that's how it was for Radek today. I had a good start to both sets, then I was solid on my own service games.
"The next thing you know, you're in the lead and you can hit freely. It was clearly a good match to start my claycourt campaign."
The Swiss, who has never won the title at the seaside Monte Carlo Country Club, will next face off for a quarter-final spot on Thursday when he takes on Lukas Rosol.
The Czech booked his spot over Frenchman Michael Llodra 6-4, 6-4.
"It's surprising the way he came through, but then again, we know he can play good tennis," Federer said of Rosol, "He's dangerous. He takes big cuts at the ball.
"On clay, on a slower surface, sometimes you get more chances to hit the ball big."
Top seed and eight-time champion Rafael Nadal, runner-up to Djokovic in last year's final, was beginning his week against Teimuraz Gabashvili of Russia.
Australian Open champion and third seed Stanislas Wawrinka was taking on Croatian Marin Cilic.
Federer improved to 14-2 over Stepanek, 35, whose last victory in the series came in Rome six years ago.
Federer, 32, swept the first set in 22 minutes and faced his only spot of bother as he saved a pair of break points in the sixth game of the second set.
The winner was aided by five Stepanek double-faults, with Federer breaking four times.
The Swiss won an ATP Tour-leading 25th match of the season.
Canadian eighth seed Milos Raonic duplicated his best showing in the principality with a 6-7 (4/7), 6-2, 6-1 defeat of Taiwan's Yen Lu-Hsun.
Italian tenth seed Fabio Fognini beat Roberto Bautista Agut of Spain 7-6 (8/6), 6-4.