The Serb was made to pay for dithering on the edge of the penalty area when Jonathan de Guzman pounced and fed Michu, who duly fired the visitors into the lead in the 39th minute.
And Ivanovic was again at fault in stoppage time when his poor back-pass was seized upon and slotted home by Danny Graham to give the Swans a two-goal cushion heading into the second leg of the semi-final at the Liberty Stadium later this month.
Benítez insisted Ivanovic’s costly errors were “no big issue” but conceded that his side have given Michael Laudrup’s men a “great advantage” in the semi-final.
“I can see any player making mistakes,” he said. “It’s not a big issue. Ivanovic was trying to do his best and the team was creating chances. It’s something that can happen, and the main thing is we have to carry on and try again.
“Obviously they have a great advantage but we have to go there, try and score a goal and we will be in the game.”
He added: “The way we played, the control we had, for me, is what we have to do. We have to be more clinical in front of goal and take these chances but we were doing a lot of these things really well.”
The Chelsea interim boss felt that the Blues were denied a legitimate goal when substitute Demba Ba had the ball in the net late on.
And the Spaniard also said that referee Anthony Taylor’s decision to book Ba for diving after he was went to ground under a Gerhard Tremmel challenge in the box was harsh.
“Watching the replay the goal was level, and so a goal,” he continued. “The penalty, the yellow card, we can talk about. It was not a yellow card but the penalty depends on the vision of the referee.”
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