Roberto Di Matteo admitted he could "not have hoped for a better result" after Chelsea ended Benfica's 10-match unbeaten home run in European competition to leave the Premier League club tantalisingly close to a Champions League semi-final against Barcelona or Milan.

The interim first-team coach conceded that his selection last night constituted something of a risk but was necessitated by a cluttered fixture schedule, with his gamble eventually paying off handsomely. Chelsea were resilient, stifled Benfica's intent and prised a precious away goal when Salomon Kalou, making his first start in the Champions League this season, poked Fernando Torres' fine pass beyond Artur with 15 minutes remaining.

Di Matteo, who saw his goalkeeping coach Christophe Lollichon dismissed three minutes from time for comments directed at the officials, praised a performance unrecognisable from that in Napoli some five weeks ago. This was their first away win in Europe in over a year. "It's terrific, we couldn't have hoped for a better result," said the caretaker manager, who had started with Frank Lampard, Didier Drogba and Michael Essien on the bench. "It was an excellent performance. We looked solid defensively and well organised and I always fancied us to score a goal.

"I didn't think [the selection] was a gamble but, sometimes in life, you have to take a little risk. We've been playing all these games recently, all of high intensity, against Manchester City, Spurs and tonight was another. It's just a question of trying to energise the team, freshen up the team. We knew Benfica play at a high tempo, so we needed fresh players who could run. That was the reasoning behind it; we needed a team with energy."

Only two teams have ever gone out of the Champions League after winning their first leg away from home, though Di Matteo preached caution. "We are pleased that we're in a different position going into the second leg from that in which we found ourselves after Napoli," said the Italian, with André Villas-Boas' team having been beaten 3-1 in Naples. "We had a mountain to climb against Napoli. We still have a mountain but it may be a little bit smaller because we've achieved a good result here."

"We've put ourselves in a good position, but it's not a result you can rely upon for the home game. It's one goal. You look at the results Benfica have achieved in this Champions League … you're not going to sleep very calmly looking at that. They've had some great results in this Champions League so we cannot think we're through yet."

The Benfica coach, Jorge Jesus, suggested the visitors had benefited principally from good fortune. "We didn't deserve to lose," he said. "We were the better side for long periods and the only time they got anywhere near our goal they scored. It was not a just result and they just had one lucky moment. But we can go to Stamford Bridge and win. We've scored in all our away games so far."

Yet confidence will be pepped at Chelsea. The players cast to the fringes by Villas-Boas do appear to be relishing the opportunities granted them by Di Matteo, with Paulo Ferreira solid on his first appearance of the calendar year here and Kalou duly scoring the winner. "I'm involving everybody that is in the squad, rotating," added Di Matteo. "We'll need everybody until the end of the season. Paulo Ferreira hasn't played for a while but was outstanding tonight for me. We cannot play with just 11 players. We need everybody in the squad.

"You'll see other players who have maybe played a little less in the past playing more of a role in the future. It's just impossible for us to play every three days and reach the fitness levels needed to win games. I'm just trying to speak to individual players, communicate and try and give them a little confidence back. I'm trying to get everybody involved, pulling in the same direction to achieve our targets."