Messi scored the opener and the third goal from the penalty spot in the 3-1 win over Arsenal on Tuesday night.
David Villa and Pedro Rodriguez with their pace and movement along with the incisive passing of Xavi Hernandez and Andres Iniesta meant the Arsenal defence were constantly on the back foot but it was Messi who unlocked the door to the defence.
He sent the Catalan side on their way with a delicate flick over the keeper and then volleyed home from close range.
Arsenal spent most of the match encamped in their own goal mouth but having drawn level through a Sergio Busquets' own goal they where left seething by the dismissal of Robin van Persie for his second yellow card, the main talking point of the night.
Whether Arsenal could have held on to the 1-1 draw with eleven men, which would have seen them go through after a 2-1 win from the first leg, is debatable but Xavi and Messi sentenced the game, while there could have been plenty more goals for Barça.
Even by Messi's own standards this season is becoming something special as he has now scored 45 goals in 39 games. He has eight from eight matches in the Champions League while domestically he has notched up 27 from 23 games.
The two goals against Arsenal mean that Messi is now top goal scorer in the history of Barcelona in European competitions aged just 23.
He has 33 goals, beating the previous record by Rivaldo of 31, and Luis Enrique, a talisman for the side in the late 1990s only had 27.
Meanwhile Messi has remained remarkably modest about his achievements and has been helped to keep his feet on the ground since his arrival at 13 by the ethos of the club to nurture the youth players into the first team.
Guardiola is the first to praise him but also emphasises the work of the players around him.
"Messi had another great game but the whole team did really well and we created a lot of goal scoring chances," said Guardiola, in the press conference after the Arsenal match.
"All the headlines will be about the goals from Messi and Xavi but in midfield we were very strong with (Javier) Mascherano and (Sergio) Busquets. We tried to improve from the first leg and we managed to press Arsenal back during the whole game.
"The only way to improve is to look in the mirror and see what you did wrong and look to correct it. That's what we did."
Messi's team-mates were quick to praise him however.
"Once again Leo has made the difference as he always does," said Xavi. "We see it every week but it is still extraordinary what he is capable of."