Frank Lampard marked his 550th Chelsea appearance with a penalty against Benfica to secure a the Champions League semi-final against Barcelona with a 2-1 win on the night and 3-1 on aggregate.
The England international slotted home from the spot midway through the first period after makeshift centre-back Javi Garcia was adjudged to have brought down Ashley Cole in the box.
Referee Damir Skomina was the main talking point of the game, though, as he handed out eight yellow cards, with Maxi Pereira sent off for the visitors for picking up two of those in the first half.
Benfica ensured a nervy ending when Garcia nodded home from close range, although Raul Meireles scored in stoppage time to ensure the Blues would face Barca in the last four.
Chelsea interim boss Roberto Di Matteo said: "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."
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."
Benfica boss Jorge 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."