Rafael Benítez said Chelsea's sense of injustice at the award of Basel's late penalty spurred his team on to an eye-catching win, though the London club's interim manager was quick to guard his victorious players against complacency ahead of next week's return.
The European Cup holders carry a narrow advantage, and two away goals, into next Thursday's game at Stamford Bridge as they seek to become the first team to follow Champions League success by securing the Europa League. David Luiz's free-kick deep into stoppage time defeated Basel, with the only concern from the evening a caution for Ashley Cole that rules the England international out of the second leg.
"It's true that we had this feeling that we didn't deserve to concede this goal, this penalty, which was an extra motivation," said Benítez, who was baffled by the Czech referee's decision to penalise César Azpilicueta for a perceived foul on Valentin Stocker despite no contact having been made. "It was not a penalty and we were surprised it was awarded. To give one, it has to be very, very clear, and no one around me felt it was a foul. I was worried when that went against us. But, in the end, though, everyone would say the win was fair.
"The feeling was that we deserved to score a second goal, and sometimes you have some good luck as a result. It was a deserved win. But we have the experience of what Basel did to Tottenham Hotspur [in the quarter-final], so we know they're a good team who can score goals home and away, so we have to be sure to concentrate next week. We can't be overconfident in the next game. We have to do our job, even if we know that, if we play well, we can beat anyone."
Benítez bemoaned the yellow card for Cole for time-wasting as "too quick" and admitted his side would miss the England full-back in the return as they attempt to reach the final at the Amsterdam ArenA on 15 May, where they would meet Fenerbahce or Benfica, with the Turkish team 1-0 up after Thursday night's first leg.
The interim manager was less critical of the official for only booking David Luiz, employed in central midfield, for a foul on Philipp Degen which might have warranted a dismissal. "They were pressing him a lot of time, and he didn't get the fouls," he said. "The foul for his yellow card was maybe right because he was a little bit late, but that's it.
"This was a very intense game played at a high tempo and we had to do our job, but we did very well. I hope this is a boost. We're working so hard, so if you can win this kind of games the mood is much better. Sunday will be a different competition against Swansea but we have to take the positives and try to keep the momentum."