Lionel Messi walked off the Camp Nou pitch in tears, as one of the most dominant eras in European club soccer came to a crashing halt.

He wasn't the only one shaking his head in disbelief.

Despite going a man and two goals down in the first half, Chelsea pulled off one of the unlikeliest comebacks in Champions League history Tuesday, earning a 2-2 draw against Barcelona. That sent the London club into the final 3-2 on aggregate and eliminated the defending champion.

For the second time in two weeks, Chelsea withstood a never-ending onslaught from the Spanish powerhouse and displayed ruthless efficiency when rare opportunities finally presented themselves.

"It's a historical night for the club. I believe we deserve to be in the final," said Chelsea's interim manager Roberto Di Matteo, whose team will face either Bayern Munich or Real Madrid in the May 19 final at Munich's Allianz Arena. "We had a difficult season, but we seem to always get something special out when we need to. That's part of the DNA of these players."

For Barcelona, the result could mark the end of one of the most successful spells in club soccer. The team was looking for a third Champions League title in four seasons, and this loss came right on the heels of a 2-1 defeat to Real Madrid that all but ended its hopes of a fourth straight league crown.

With coach Pep Guardiola yet to decide whether to stay at the club, it means his reign could end without a major crown this year — although the Copa del Rey is still up for grabs as a consolation.

"It hurts to lose this way because we were better and we gave it our all," said Barcelona midfielder Cesc Fabregas. "We needed the perfect game, but we weren't perfect because we lacked goals."

Despite coming into the second leg with a 1-0 lead, Chelsea's hopes looked all but over after going down 2-0 and having captain John Terry sent off for a needless foul in the first half.

But Ramires' stunning lob right before halftime gave the advantage back to the Blues on away goals, and Barca never found a way to recover after the break. After Messi blasted a penalty kick against the crossbar and hit the post with another shot, substitute Fernando Torres scored in injury time to make it 3-2 on aggregate and ensure that Chelsea advanced.

While Chelsea's players celebrated, Messi trudged off the field with his head buried in his shirt.

"We're here because of this kid," Guardiola said. "I have no doubt he's going through a bad moment. That's the sad thing about this sport is that these things exist."

For Chelsea, this was the crowning achievement in a remarkable and improbable turnaround led by di Matteo, who has also guided the team into the FA Cup final after manager Andre Villas-Boas was fired in March.

Chelsea won the first leg 1-0 at Stamford Bridge last week after Didier Drogba scored with the hosts' only shot on target amid a series of wasted chances by Barcelona.

It is Chelsea's first Champions League final since losing to Manchester United in a penalty kicks shootout in 2008, and gives owner Roman Abramovich another chance to finally capture the elusive title in Europe's premier club competition.

Sergio Busquets and Andres Iniesta put Barcelona up 2-0 by the 44th minute as the Spanish club again dominated possession from the start — owning 73 percent for the game. In between those goals, Terry was given a straight red card for putting his knee into the back of Alexis Sanchez, making a Chelsea rally look even more unlikely.

"I feel as I let them down, I've apologized to them," said Terry, who will be suspended from the final alongside another three Chelsea players. "Looking at the replay, it does look like a red card."

But just like at Stamford Bridge, Chelsea was very opportunistic once it created a rare counterattack.

Ramires ran onto a long through ball from Frank Lampard to send an impressive lob over Victor Valdes to boost the visitors just before halftime.

"With 2-0 at halftime we would have believed we could get it, but this 2-1 was a little bit psychologically bad for us," said Guardiola, whose team also lost Gerard Pique in the first half to a concussion. "The penalty we didn't score and they got stronger."

Barcelona's inability to convert its possession advantage into goals was symbolized by Messi's rare miss from the penalty spot in the 49th; the Argentina winger is scoreless in seven meetings with Chelsea. Barcelona hasn't been able to beat Chelsea in the last seven meetings, either.

Three-time FIFA player of the year Messi, who has 63 goals this season, hasn't scored in his last three games.

Torres, who has struggled all season, was sent clear in injury time, went around Valdes to put the ball into an empty net for his eighth goal in 11 games against Barcelona.

"We knew this is how we had to play against Barcelona, even if sometimes it's not so attractive," said Torres, who replaced Drogba with 10 minutes left. "We used our strengths well and it worked for us in both games. They had their chances but they didn't finish and Ramires' goal gave us life."

Chelsea will be missing Terry, Ramires, Branislav Ivanovic and Raul Meireles for the final.