Top seed Federer, who was given a first round bye, took 74 minutes to extend his flawless record against the 21-year-old Spaniard to 4-0 in blazing sunshine at the Foro Italico.

The only other second round match taking place on the second day sees Croatian eighth seed Ivan Ljubicic up against Jose Acasuso of Argentina.

Federer, who has never won here, admitted he wasn't at his best against Alamagro.

"First round matches are always tricky and I'm just glad to get through to the next round as Nicolas is a difficult opponent," said the 25-year-old Swiss who lost to Rafael Nadal in last year's final, and to Felix Mantilla in the 2003 final.

Federer said it was about time he added the Rome tournament to his 12 Masters Series titles.

"I've played here many times and I have been to the final twice, so I feel like I've almost won it," he said.

"I'm here again and I feel I have a chance. I would love to win it."

In first round matches, American ninth seed James Blake defeated Frenchman Gael Monfils 6-4, 6-4, while Russian Marat Safin, the 2000 US Open champion, battled back from a set down to beat American Amer Delic.

Safin, who has never gone beyond the third round here, will next face fourth seed Nikolay Davydenko in round two.

Cypriot Marco Baghdatis, runner-up at the Australian Open last year, defeated Spaniard Carlos Moya, Rome champion in 2004, in straight sets.

German 11th seed Tommy Haas was forced to retire with a right shoulder injury in his match against Czech Radek Stepanek, with Stepanek leading 6-3, 3-2. Stepanek will now meet Baghdatis in round two.

Spanish second seed Nadal, the world number two and Rome champion for the past two years, begins the defence of his title on Wednesday against Italy's Daniele Bracciali.

Nadal, who extended his record clay court winning streak to 72 matches when he won the Barcelona Open last month, is aiming to become the first player to win the Rome tournament - a warm-up for the French Open which starts on May 27 - three times in a row.