Relief was the overwhelming emotion for Frank Lampard as Chelsea edged past 10-man Benfica to set up a Champions League semi-final showdown with Barcelona.
Lampard scored from the spot after Javi Garcia had brought Ashley Cole to put his side 2-0 up on aggregate, but Benfica ensured a tense finish when Garcia nodded home from close range on 85 minutes.
Raul Meireles scored in stoppage time to finally seal Chelsea's place in the last four, where they will face the defending European champions, but Lampard conceded the Blues had made hard work of their progression.
"Yeah, it was a tough game,'' Lampard told ITV1. "Winning 1-0 away leaves you in a bit of a conundrum how to approach the game. We gave them an idea they could come and win the game.
"We didn't want to go too gung ho but we created enough chances tonight in the second half. We are pleased to be in the semis.''
Asked if Chelsea have some unfinished business against Barcelona after previous controversial clashes, most notably the semi-final of 2009, Lampard added: "Everyone has unfinished business with them.
"They are the greatest team in the world. They are going to be favourites but we have a lot of belief in ourselves. We have to perform at our best to beat them and we believe we can do that.''
Chelsea interim boss Roberto Di Matteo added: "We knew before the game we were going to face a difficult game tonight and it proved that.
"Benfica are a good side, but we are pleased we are in the semi-final now. The second goal was missing to kill the game. With a 1-0 lead they still had a chance and they knew that. We missed a lot of chances to kill the game.
"We probably made it a little bit more difficult for ourselves by not scoring a second goal, especially in that second half with all those chances. That kept them alive and [gave them] hope that they would score a goal and still be in it.
"They moved the ball around very nicely. We didn't quite keep possession enough as we'd have liked to with the extra man. I think the team wasn't as sparkling as we were hoping it would be. Maybe they were a bit tired, but we're pleased to have won the game and gone through. We deserved it over the two legs.''
Asked about facing Barcelona in the last four, Di Matteo added: "Let me enjoy this first of all. We play Wigan on Saturday and we have to focus on that first.
"They [Barcelona] are probably one of the best teams in the world, if not the best. We are excited to be able to play a semi-final against a big team.
"We will find a strategy that will suit our players and our team to face Barcelona. I think it will be a combination [of playing to our strengths and attempting to cancel out their players]. They obviously have some individual players that are a big threat and very dangerous, but we also have to play our game and play to our strengths.''
One blot on Chelsea's evening was an injury to captain John Terry. The 31-year-old looked superb in central defence but had to be replaced in the 59th minute by Gary Cahill.
"He got a knock on his rib and that's why we had to take him off,'' Di Matteo said. "We'll assess him tomorrow and see how he is. We hope that he is going to be okay.''
Benfica manager Jorge Jesus felt his side deserved to progress and felt particularly aggrieved by the performance of referee Damir Skomina, who handed out eight yellow cards - including two to Pereira - on the night.
"Well, we've been the better team in both legs - in Lisbon and in London,'' he said. "I am very proud of my men. We played with 10 men for the best part of an hour and we were still the better team. We made Chelsea look ordinary.
"We were penalised by the referee tonight, unfortunately, and unjustly I feel, but that's football in the end. We come away as losers but I feel my team gave everything and I am very proud of my players tonight.
"We didn't look as if we only had 10 men out there tonight. We looked as if we had 11 men. It turned out that Petr Cech was their best player, he is obviously a great keeper and he made some great saves tonight.
"Moreover, Chelsea have some great individual players, there's no denying that. Still, my players came back in the second half even though we were down to 10 men, pushed them back in the final third and pinned them back for most of the game.
"In the end, even after coming back to 1-1 we nearly scored in the end and missed a couple of very good chances before suffering on the counter-attack.''
While Benfica rarely looked like the side that twice managed to hold Manchester United in the group stages, Jesus was quick to dismiss Chelsea's prospects of overcoming Barcelona in the next round.
"I can't understand how we're out,'' he said. "What hurts me is that we've knocked out better teams than this Chelsea. That's what leaves me with a certain sense of revolt. I may be wrong but I believe Chelsea have no chance against Barcelona.''end