Nadal collapsed on the court when he clinched victory after over five hours

Nadal came back from 4-2 down and saved two match points in the final set before triumphing 6-7 (0-7) 7-6 (7-5) 6-4 2-6 7-6 (7-5) in a thrilling final.

The win, which took over five hours, takes Nadal to 53 straight wins on clay, matching Guillermo Vilas' record.

It also puts the 19-year-old level with Bjorn Borg on 16 titles as a teenager.

"It's something I don't think I'll ever do again," Nadal said of reaching 53 straight wins.

"But it was more important to win the Rome title."

Nadal, whose last defeat on clay was against Igor Andreev in April 2005, will overtake Vilas if he beats Tommy Haas in the first round of this week's Hamburg Masters, and could go on to take Borg's record if he clinches the title.

However, his participation in Hamburg, as well as Federer's, must be in doubt after a gruelling final in Rome - the longest match of the year so far.

Photos of the Rome final

Federer, who has beaten Nadal only once in five attempts, started well, clinching a high-quality first set after playing a near-perfect tiebreak.

And the world number one was on top for most of the second set but Nadal's trademark battling qualities kept him in it and out of the blue, he somehow earned a set point at 5-4.

The teenager was unable to take that one but edged another tiebreak to draw level.

The momentum was by now with Nadal and he looked to have made a decisive move when a break at 2-2 gave him the third set.

CLAY-COURT WINNING STREAKS 53 Guillermo Vilas, May-Oct 77 53 Rafael Nadal, Apr 05- 46 Bjorn Borg, Oct 77-May 79 40 Thomas Muster, Feb-Jun 95 38 Muster, Aug 95-Apr 96

He had chances to break early in the fourth set but the Spaniard let his struggling opponent off the hook and Federer made him pay.

The top seed raced through the fourth set and took control of the decider by taking a 4-2 lead.

The Rome crowd, including Prince Albert of Monaco and Omar Sharif, looked on in disbelief as first Nadal levelled at 4-4 then fought off Federer again at 5-6.

Nadal's double fault, the first of the match from either player, helped Federer earn two match points but the world number one's usually impeccable forehand failed him on both occasions and the Spaniard survived.

Federer still had chances to win in the tiebreak which he led until the death, in particular when he mishit a forehand which would have given him a 6-3 lead.