Juventus celebrate in Rome's Olympic Stadium [AFP]

The Brazilian struck in each half to secure Juventus' second win of the season before Felipe Melo scored in second half injury time to kill off any hopes Roma may have had of a late rally.

"It was as hard as we thought it would be,'' Diego said, "but you have to work hard to get anything against a side of this quality. There is a great atmosphere here at Juventus and with coach Ciro Ferrara and all the players, it has allowed me to settle into the team quickly.''

Roma equalised when Daniele De Rossi opened his account for the season in the 35th minute, but Luciano Spalletti's charges were unable to come back a second time

The result means Roma is bottom of the table with no points.

After a quiet 20 minutes, fullback Paolo De Ceglie went close when his header from Diego's freekick forced Roma goalkeeper Julio Bertagnoli to push the ball away for a corner.

The next chance fell to Diego and he took full advantage, breaking through midfield, brushing off defender Philippe Mexes and then flicking the ball over Bertagnoli.

De Rossi's equaliser came as a surprise. Taddei flicked the ball to him in midfield and from well outside the area he fired a long range shot past Italy international Gianluigi Buffon.

Juventus striker Amauri went close on two occasions, but it was Totti who had the best chance for Roma before halftime.

Jeremy Menez played him through on goal, but Buffon rushed off his line to palm Totti's shot to safety.

After the break Amauri went close twice and Vincenzo Iaquinta shot over when one-on-one with Bertagnoli.

In the 67th Diego scored his second. Fabio Cannavaro picked out Iaquinta, who flicked the ball into Diego's path and the midfielder made no mistake to give Juventus the lead.

As Roma chased an equalizer and Mirko Vucinic headed wide and captain Francesco Totti struck a post 10 minutes from the finish, but Melo's late goal from the edge of the area sealed the win.

Stevan Jovetic was rewarded with a starting place for Fiorentina after he had come on and turned the match around on Wednesday against Sporting Lisbon.

After five minutes he went close to opening the scoring, but Palermo goalkeeper Rubinho was equal to his shot and Alberto Gilardino couldn't turn in the rebound.

But in the 29th minute the Montenegrin did open the scoring when he redirected Gianluca Comotto's cross past Rubinho, who was totally wrong-footed.

Just before halftime Fabio Miccoli forced Fiorentina keeper Sebastien Frey to save well with a sharp shot from close range after he had found space in the area.

Both teams tired quickly in the second half, but it was Fiorentina who came the closest to adding to the score.

In the 49th Alessandro Gamberini nearly took advantage of a mix up in the Palermo defense after Juan Vargas' freekick and in the 70th Jovetic turned sharply, but fired wide from the edge of the area.

"He's an excellent player and he put himself about for the team today,'' Fiorentina coach Cesare Prandelli said.

"He can develop more with us and tonight he provided a tonic for Fiorentina for at least an hour.

"Adrian (Mutu) had a muscular problem and we gave him a test on it yesterday, but he couldn't have been on the bench, because he wouldn't have had enough time to warm up if he had to come on,'' Prandelli added.

Elsewhere, two strikers strengthened their cases for inclusion in Marcello Lippi's Italy squad for the upcoming matches with Georgia and Bulgaria.

Fabio Quagliarella scored twice for Napoli in its 3-1 win over Livorno, whilst Giampaolo Pazzini opened the scoring for Sampdoria as it beat Udinese 3-1.

Also Sunday, it was; Atalanta 0, Genoa 1; Cagliari 1, Siena 3; Chievo Verona 1, Lazio 2, and Parma 2, Catania 1.