, knock them out ue with 2-1 victory an United 3-0 to reach semis
vanced 4-0 on aggregate.
Messi opened the scoring with a brilliant solo effort in the 16th minute after he won possession of the ball, ghosted past a defender, and curled a shot into the far corner.
The second came just four minutes later, although Messi was helped by a massive error by David de Gea that time. The Argentina forward only managed a tame shot on goal but the Spain goalkeeper let it slip underneath him and into the net.
Philippe Coutinho added a third goal with a superb curling strike from long range in the 61st to cap arguably the best performance by the former Liverpool player since joining Barcelona just over a year ago.
Twenty years ago at Barcelona's stadium, United manager Ole Gunnar Solskjaer completed one of the most memorable comebacks in soccer history when he scored the English team's second injury-time goal to stun Bayern Munich in the 1999 Champions League final. But after a promising start when Marcus Rashford hit the crossbar, Messi showed that sentimental memories mean very little when he is playing at his best.
The goals ended Messi's bizarre scoring drought in Champions League quarterfinals that had reached 12 matches dating back to 2013.
They took his tournament-leading tally to 10 this season. In total he has 45 goals in 42 games through all competitions.
Police stop 54 weaponcarrying Ajax fans ahead of Juve game
Italian police stopped 54 weapon-carrying Ajax supporters before Tuesday's Champions League match against Juventus and will escort them out of the country.
The fans were stopped aboard buses on the outskirts of Turin on Monday.
Police were on high alert following clashes between Ajax and Juventus supporters ahead of the first leg of the quarterfinals in Amsterdam last week, when water cannons were used by the authorities and dozens of fans were arrested.
Turin police say the fans aboard the buses were also found in possession of armored gloves, mouth guards and various types of fireworks and smoke bombs.
"We're fighting against every type of violence inside and outside stadiums," Interior Minister Matteo Salvini tweeted. "Certain DELINQUENTS should never step foot in a football ground again!"
The first leg, which ended 1-1, also included a fan jumping over the barriers and approaching Cristiano Ronaldo when the Juventus star scored.
UEFA is investigating the incident and Ajax faces disciplinary charges after supporters threw objects the game.