Barcelona all but secured their spot in the Champions League semi-finals and a probable showdown with arch rivals Real Madrid after building a huge first-leg lead over Shakhtar Donetsk.
Following on from Madrid's 4-0 thumping of Tottenham last night, Barca appear to have done all the hard work in their home quarter-final tie after another memorable European night at the Nou Camp.
Andres Iniesta, Dani Alves, Gerard Pique, Seydou Keita and Xavi were on the mark for the Catalan giants, while Shakhtar's sole reply came from Yaroslav Rakitskiy when they were already 3-0 down.
Barca coach Pep Guardiola admitted yesterday he had a bad feeling about this match, but his fears will have been eased after seeing his take the lead after just 99 seconds through new father Iniesta.
The Spanish World Cup winner, whose wife gave birth on Sunday, slotted a low shot past visiting goalkeeper Andrei Pyatov at his near post after picking up a loose ball in the area.
However, 10 minutes after that goal, Barca survived two huge scares in quick succession as they rode their luck at the back.
The first opportunity saw Luiz Adriano beat stand-in Barca centre-back Sergio Busquets to a through-ball but then fire wide with only Victor Valdes to beat.
Then, just moments later, a bad attempted back-pass from Dani Alves forced Valdes to race out of his goal and, although he beat Luiz Adriano to the ball, his clearance went straight to Willian whose first-time shot from 30 yards out dropped just wide of an open net.
Barca survived though and almost profited from some slack defending themselves in the 19th minute, as Messi robbed Mykola Ischenko of possession on the edge of the Shakhtar area but his attempted chip over Pyatov was saved.
Barca, who also went close through a Messi free-kick and a David Villa shot, were celebrating a second goal soon enough though as Alves netted after latching onto an inch-perfect pass by Iniesta.
Iniesta's lofted ball in towards the penalty spot might have been collected by Pyatov but, as the goalkeeper waited for the ball, Alves nipped in to steal possession before slotting into an empty goal.
That was the score Barca led by at half-time, but the 2006 and 2009 European champions wasted no time in trying to build on that advantage at the start of the second period.
Messi and Xavi both had efforts saved before Guardiola's side made it 3-0 in the 53rd minute through Pique following a training-ground move.
Xavi cut a low corner back towards the edge of the area to meet the run of Pique, who had escaped his marker, and the Spain centre-back's first-time shot took a deflection off Rakitskiy before beating the wrong-footed Pyatov.
At that point Barca looked to be cruising into the semi-finals but Shakhtar gave themselves a glimmer of hope after netting an away goal in the 58th minute, with Rakitskiy making the decisive touch at the right end this time.
Darijo Srna's free-kick into the area was flicked on by Rakitskiy at the near post and Valdes was unable to keep the ball out as it flew into the far side of the goal.
Shakhtar's hope was short-lived however as Barca immediately went down the other end and restored their three-goal lead.
Messi beat his man before rolling a pass across the edge of the area to the unmarked Keita, who slammed an unstoppable shot into the near top corner of the net.
Barca survived another let-off with nine minutes remaining when Luiz Adriano struck the inside of the far post, and if that had gone it in would have made for an interesting second leg.
However, the ball stayed out and Barca all but killed the tie off by notching a fifth goal in the 86th minute when Xavi slotted in Alves' pass.