Inter Milan coach Jose Mourinho has said Chelsea should have had a penalty, but he also accused Salomon Kalou of "diving at the right moment".
Kalou went down under a clumsy challenge from Walter Samuel just before half-time when the score was 1-0 to the home side.
Spanish official Manuel Gonzalez waved away the Chelsea protests with Kalou going on to grab an equaliser before Esteban Cambiasso restored Inter's advantage ahead of the second leg.
Kalou was quick to refer to the incident post-match and while Mourinho accepted it ought to have been a spot-kick, he also claimed the Ivory Coast striker knew what he was doing when he hit the turf.
"We were a bit lucky," he told Sky Sports, "but Kalou was clever. He dived at the right moment. Normally it's a penalty.
"The referee looked over to the linesman and the linesman told him no."
Mourinho was happy to have eked out a narrow lead before his eagerly-awaited return to Stamford Bridge.
He added: "It's an advantage. It's different to go there with a draw or a defeat than to go there in front.
"When the game starts at Stamford Bridge, in the first second of the game Inter will be in the quarter-finals and Chelsea will be out.
"After that we will see, there will be another 90 minutes but at the start...
"Mentally that is an advantage."
Mourinho was on Thursday hailed by Inter owner Massimo Moratti for getting the better of former AC Milan boss Carlo Ancelotti, now in charge of the west London club.
"I had no doubts about my team. Knowing my players and, above all, knowing Mourinho, who had prepared this match well," he said on www.inter.it.
"Putting on (Mario) Balotelli at the end of the match is typical of a coach who thinks about the best victory rather than about himself.
"He knows how to change his team with different systems and change it according to the situation."
