Barcelona vs. AC Milan: 5 Things We Learned from Champions League Quarterfinal

After a stalemate at the San Siro, Barcelona beat AC Milan 3-1 at Camp Nou to advance to the UEFA Champions League semifinals—for the fifth season in succession.

Pep Guardiola's team needed two disputed penalties to get past Milan, but there can be no argument Barca were deserving winners of the tie.

Here are five things we learned across the two legs.

Messi Will Find a Way

Milan swarmed around Lionel Messi every time he picked up possession, but they could not stop the diminutive genius from making an impact.

We knew this already of course, but there really is no way of stifling Messi—beyond bringing him down.

All you can do is try to guide him away from goal and try not to commit so many defenders as to leave his teammates wide open for a pass.

If Chelsea progress against Benfica, they may very ask a player like John Obi Mikel or Raul Meireles to track Messi. Good luck to whoever gets the job.

Barca Are Vulnerable Early On

There's no question Barca grow stronger as games go on. Almost unfailingly, Guardiola's team eventually settles into a hypnotic passing pattern and by the final 15 minutes, Barca's opponents are generally chasing shadows.

The key to beating them is to hit them first and hit them hard. Milan had chances early on at the San Siro and Camp Nou, but they simply didn't take enough of them.

The same was true when Madrid lost 2-1 at the Bernabeu in January and 3-1 last December.

Quick Breaks Are the Key

With Barcelona generally committing a large number of players forward as they advanced into the final third, Milan looked at their most dangerous on the break.

If you do manage to win the ball back from Barca, the key is to drive forward with pace and be as direct as possible.

Both Real Madrid and Bayern Munich are well equipped for blazing counterattacks, which should make for a fascinating coming together in the final—assuming Barca get past Chelsea or Benfica.

Barca Have Earned the Respect of the Officials

Barcelona were awarded two penalties at Camp Nou. The second in particular drew fierce protests from the Milan players and their manager, Massimiliano Allegri, but you could argue that Barca have earned the sympathy of officials through their magnificence in recent years.

The lesson for whoever faces them next, be it Chelsea or Benfica, is for defenders to stay on their feet in the box and not give the referee the slightest excuse.

As Guardiola rightly said after the game (via the Daily Mail), both penalties were given for fouls inside the box. Whether both would have been given to Milan is another question entirely.

Little Chance of a Coup at Camp Nou

Milan had a brief glimmer of hope at Camp Nou, but they were ultimately seen off in predictable fashion by a Barcelona team who have lost just three times in 72 league matches there since Guardiola took over.

On average, Barca have 19 shots to their opponents' six at Camp Nou, with 70 percent possession (courtesy of whoscored.com).

To get past them in the semis, Chelsea or Benfica will surely have to gain an advantage from their home leg, which comes up first.