Juventus were poised to open up a 12-point lead over their opponents at the top ofSerie A after Roma had Vasilis Torosidis sent off and Carlos Tevez put the visitors in front from a free kick.

Instead, Juventus lost concentration and finished the game on the back foot afterSeydou Keita levelled for Roma.

"I was angry when we left the pitch," Allegri told touchline television reporters.

"Considering the way the match was going, it's disappointing to come away with a draw and to have run the risk of losing the game. We've conceded too many goals recently and we need to make better use of possession when we're in front."

"I'm happy with what we did in the first 70 minutes and we continued playing well for a while after taking the lead, but after six or seven minutes we stopped playing," he added.

Although Juventus, with a nine-point lead, are still well on course for a fourth successive Serie A title, Allegri said there was a long way to go.

"We need to improve as we sometimes lose our focus," he said. "We are still a long way off our target. It's not easy for Roma but there are still plenty of points up for grabs."

Tevez only the took the free kick because playmaker and specialist Andrea Pirlo was missing through injury.

"I was trying to copy him," the Argentine told reporters. "He inspires me, I watch him in training."