Lionel Messi sent more records tumbling as holders Barcelona beat AC Milan 3-1 on Tuesday to reach the Champions League semi-finals, while Bayern Munich completed a 4-0 aggregate win over Marseille.

The 24-year-old Messi reached the 50-goal mark in Europe's premier club competition with an early penalty at Camp Nou that also saw him break the record he jointly held with Ruud van Nistelrooy for most goals in a Champions League season.

After Antonio Nocerino had equalised to make it 1-1 and put Milan ahead on away goals, Messi claimed a second penalty to match former Milan striker Jose Altafini's 1962-63 record of 14 goals scored in one European Cup campaign.

A second-half goal from Andres Iniesta completed victory for Pep Guardiola's men, who became the first team to reach five consecutive semi-finals in the competition since the great Real Madrid side of the late 1950s.

Barca will bid to reach a third final in four seasons against either Chelsea or Benfica, who meet at Stamford Bridge on Wednesday with the English side leading 1-0 on aggregate.

"When you play against a team like Milan, you know the job is never done until you hear the final whistle," said Iniesta.

"We had to work really hard against a great side and we are thrilled to be in the semi-finals. Let's see what happens in tomorrow's game and who we'll face in the next round."

Xavi and Cesc Fabregas both overcame injury doubts to start at Camp Nou, where Milan began the game needing just a score draw to progress following the 0-0 stalemate between the sides in the first leg at San Siro last week.

Messi had already threatened twice by the time he broke the deadlock in the tie in the 11th minute, placing a penalty into the bottom-left corner after he had been felled by Luca Antonini's sliding tackle.

Barca were dominant but Guardiola had predicted that Milan would score and so they did in the 32nd minute, with Nocerino sliding home from Zlatan Ibrahimovic's reverse pass.

It took the hosts just nine minutes to restore their lead, however, with Messi sending penalty number two into the bottom-right corner after referee Bjorn Kuipers had bravely penalised Alessandro Nesta for holding Sergio Busquets' shirt.

Milan's hopes of a comeback receded sharply in the 53rd minute when Iniesta lifted Barca's third past visiting goalkeeper Christian Abbiati after Messi's shot was blocked to cement the Catalans' place in the last four.

"You have to play the perfect game to win here and unfortunately we made some mistakes, both in defence and in attack," said Milan coach Massimiliano Allegri.

"We were all disappointed during the interval after conceding late in the first half. When we came out for the second half, we conceded another at a crucial time."

Having seen his side win 2-0 at Stade Velodrome last week, Bayern coach Jupp Heynckes elected to start with Arjen Robben and top scorer Mario Gomez on the bench at Munich's Allianz Arena, which will host the final on May 19.

Gomez's replacement, Ivica Olic, took full advantage of the opportunity to shine, converting low crosses from Franck Ribery and David Alaba to put Bayern 2-0 up by the interval.

"We were very concentrated, despite the amount of games we are playing at the moment," said Heynckes, who is attempting to guide his side to a treble of trophies in the Champions League, Bundesliga and German Cup.

"Marseille weren't in the quarter-finals for nothing and they tried everything."

Suspended for the first leg, Marseille goalkeeper Steve Mandanda kept the scoreline respectable thereafter but OM -- ninth in Ligue 1 -- have now gone 10 games without a win in all competitions.

"We lost to a great team, but we did not give up," said striker Loic Remy.

"Hats off to Bayern, I hope they go all the way. We still have the League Cup final (against Lyon on April 14) to look forward to and we want to do well in the league."

Bayern will play either Real Madrid or Cypriot representatives APOEL in the last four, with Madrid carrying a 3-0 lead into Wednesday's second leg at the Bernabeu.