After 14 titles in five seasons, Barcelona was still lacking the epic comeback to put some added drama into its unprecedented winning run.
Lionel Messi crossed that one off the list on Tuesday.
Messi scored a brilliant brace to help Barcelona beat Milan 4-0 and guide his side into the quarter-finals of the Champions League.
Barcelona won 4-2 on aggregate after a spectacular second leg in the last 16, entering the record books as the first team to turn around a 2-0 first-leg away loss in the competition.
The four-time champion imposed its attack from the start and Messi finished off a team move just five minutes in to give the hosts a huge boost before a screaming crowd of 99,786 at Camp Nou, Europe's largest stadium.
Messi struck with another left-footed strike in the 40th to level the contest over two legs. And Barcelona's relentless pressure paid off in the 55th when David Villa netted the decisive goal before Jordi Alba added a fourth in stoppage time.
"It had been a long time since we had pulled off a historic comeback," said Barcelona midfielder Xavi Hernandez. "We pressed them very well and played an exceptional match."
Barcelona joins Galatasaray in the last eight after the Turkish side beat Schalke 3-2 on the night and 4-3 on aggregate.
Against the odds, Barcelona reached the quarterfinals for a sixth straight season and kept alive its bid for a fourth title in eight years.
Barcelona had failed to fight back after losing first-leg away semifinals to Chelsea last season and to Inter Milan in 2010.
'For anyone who doubted [Lionel] Messi, today Messi gave a lesson on how to play football. He is extraordinary, and surrounded by great players, he is capable of doing what he does.'—Barcelona assistant coach Jordi Roura
Messi made sure they got it right on a third try, and did so in style with his 52nd and 53rd goals of the season.
The four-time world player moved past Ruud van Nistelrooy (56) into sole possession of second place on the Champions League career scoring list with 58 goals at just 25 years old, trailing only Raul Gonzalez's 71.
"For anyone who doubted Messi, today Messi gave a lesson on how to play football," said Barcelona assistant coach Jordi Roura, who has been in charge since January, with manager Tito Vilanova in New York for treatment for a throat tumour. "He is extraordinary, and surrounded by great players, he is capable of doing what he does."
The sluggish Barcelona from the loss at San Siro three weeks ago and its two recent defeats to fierce rival Real Madrid was nowhere to be seen on Tuesday night.
Barcelona put on yet another breathtaking display, the kind that has earned its place among the best teams to have played the game.
It went forward with orchestrated precision both in its passing and shot taking, and defended tenaciously, asphyxiating Milan's attack before it could ever get started.
Messi had already pulled one goal back for Barcelona before Milan was even able to get the ball, much less string two passes together.
Barcelona scored early through an exquisite flurry of one-touch passes that had eluded it in recent matches. Messi received Sergio Busquets' pass outside the area, laid the ball off for Xavi, who slid it back for Messi to unleash a curling strike that left goalkeeper Christian Abbiati helpless as it ripped into the top left corner of his net.
"We went out gunning from the start and scoring early helped us," said Villa. "We have believed in the comeback ever since we lost in Milan, and belief combined with hard work is how you achieve things."
Milan's lack of ball control allowed Barcelona to dictate the contest and keep most of the action in the final third of the pitch.
Even so, an error by Javier Mascherano gave Milan the perfect chance to score in the 38th when he headed a high ball back toward his own goal. M'Baye Niang raced onto the ball and shot past the onrushing Valdes, only to see his strike hit the left post.
Just two minutes later Messi levelled the series when Andres Iniesta stole the ball in Milan's half and passed to his teammate on the edge of the area. Messi quickly put the ball on his left boot and rifled a shot under Philippe Mexes' legs and the outstretched Abbiati to send the home crowd into ecstatic chants of his name.
"Barcelona is still the best team in the world, moving on was a true feat," Milan coach Massimiliano Allegri said after his team's first four-goal defeat since losing by the same scoreline at Manchester United in 2010.
"The first leg didn't change these two teams, and whoever thought so was wrong. We played worse than in the first leg, but that is to Barcelona's credit."
Barcelona turned the tie in its favour for good thanks to its aggressive defending. Mascherano surged forward to intercept a pass inside Milan's territory, with the ball passing through Iniesta to Xavi, who fed a through pass by the sliding Kevin Constant for Villa to size up Abbiati and swerve a strike into the far side of the net.
Milan still got once last-gasp opportunity from substitute Robinho, but Alba hustled back to block his close-range attempt in the 82nd.
Alba then sealed the win when he raced the length of the field on a counterattack keyed by a Messi pass in the second minute of injury time.
Galatasary edges Schalke
Galatasaray beat Schalke 3-2 on Tuesday to advance to the Champions League quarter-finals with a 4-3 victory on aggregate.
Substitute Umut Bulut scored the winner in the fifth minute of stoppage time, though Galatasaray was already through with a 2-2 draw on the away goals rule.
Barcelona also advanced with a 4-0 win over AC Milan, overcoming a 2-0 deficit from the first leg.
Roman Neustaedter put Schalke ahead in the 17th minute but Galatasaray fought back with two goals before halftime. Hamit Altintop scored with a long-range shot against his former team in the 37th and Burak Yilmaz put the Istanbul side in front in the 42nd, with his competition-leading eighth goal of the season.
"We took the game under control in the first half," Altintop said. "Both matches were close, though, and both sides had their chances. We were the luckier team today.
Michel Bastos levelled in the 63rd and Schalke missed several chances after that to win the match before Bulut finished a counterattack to put his team in the last eight of the Champions League for the first time since 2001. Galatasaray, held to a 1-1 draw at home, won its third match on the road this season in the competition.
"We invested too little in the first half, it's a bitter disappointment. We made stupid mistakes," Schalke captain Benedikt Hoewedes said.
Schalke came under pressure early in the match.
Didier Drogba shot wide, then released Selcuk Inan, whose weak finish was no problem for Schalke goalkeeper Timo Hildebrand.
But it was Schalke that scored first.
Jefferson Farfan's corner left Galatasaray's defence in disarray and Howedes' header was blocked before the ball fell to Neustaedter, who drove past Fernando Muslera.
"We never got into the match, we slept through the first half," Schalke coach Jens Keller said. "We scored the goal but it failed to settle us down. We were not aggressive enough."
Wesley Sneijder's sent a curling shot just wide, before Altintop levelled against his hometown team, where he spent four seasons. He unleashed a shot from some 30 metres (yards) out, and the ball hit the inside of the post before bouncing into the net.
Yilmaz put Galatasaray ahead after Albert Riera stole the ball from Marco Hoeger in the Schalke half and it fell into the forward's path. Yilmaz shook off Hoewedes and beat Hildebrand.
However, Hildebrand did well to tip away another effort from Yilmaz after the break.
Schalke's Julian Draxler shot wide after sliding past Felipe Melo and Semih Kaya, shortly before the home team levelled.
Goalkeeper Muslera made a good save at the feet of Teemu Pukki but the loose ball came to Atsuto Uchida, who found Bastos to score from close range.
Sneijder then saw another effort go wide, and Muslera made two more saves to deny Draxler.
With time running out, Bulut collected a through pass from Selcuk Inan and sealed the win. His first effort was parried by Hildebrand but Bulut made no mistake the second time.