The result interrupted Roma's sequence of 11 consecutive league wins.

Inter are third in the table with 59 points from 28 matches, three points ahead of Fiorentina who climbed to fourth with a 2-1 win over Siena. Roma slipped to fifth on 55.

Juventus (73 points) and AC Milan (63) occupy the top two places after respective wins over Sampdoria and Empoli on Saturday.

"We didn't take advantage of one or two of the chances we created on the break, but the result is a fair reflection of the match," Roma coach Luciano Spalletti told Italy's SKY television.

"We are still in the race for fourth place. There are 10 matches to go and a lot can change between now and the end of the season."

Roma and Inter had early chances at the Olympic Stadium.

Home keeper Doni dived to his near post to stop an Alvaro Recoba shot while at the other end Francesco Toldo palmed out Rodrigo Taddei's free-kick.

Roma broke the deadlock in the ninth minute when Brazilian winger Mancini dribbled into the area, rounded defender Materazzi and cut the ball back for Taddei to score.

Inter steadily grew in confidence and went close to equalising before the interval when Doni saved a volley from Esteban Cambiasso.

The visitors kept up the pressure after the break although Roma almost made it 2-0 when Mancini, alone on goal, fired over.

As they did in the first half, Inter finished the second period on the attack by winning a series of corners and pushing Roma back to the edge of their area.

The pressure paid off a minute from time when Materazzi headed a corner in at the near post.

Fiorentina's fans must have anticipated an easy victory over mid-table Siena when Serie A's top scorer Luca Toni muscled in front of his marker to sidefoot Stefano Fiore's cross past keeper Marco Fortin in the third minute.

Only a full-stretch save by Fortin prevented Toni from heading his 24th Serie A goal of the season soon after.

Siena struck back after 15 minutes, Enrico Chiesa breaking down the left before unleashing a dipping shot that Bogdan Lobont spilled for Simone Vergassola to score.

Visiting Siena had chances each side of halftime to take the lead. Tomas Locatelli headed narrowly wide from a Chiesa cross and a mistake by defender Dario Dainelli allowed Erjon Bogdani to run through alone before Lobont turned his shot round the post.

In the first minute of stoppage time, Luis Jimenez's header from a free kick forced a reflex save by Fortin and, in the goalmouth scramble that followed, striker Giampaolo Pazzini netted.

Livorno's grip on sixth place, Italy's final UEFA Cup berth, loosened when they lost 1-0 to a goal by Cagliari striker David Suazo.

The defeat left Livorno on 44 points, three ahead of Chievo Verona, who drew 2-2 with Lazio.