Spanish duo Barcelona and Atletico Madrid became the latest sides to qualify for the Champions League last 16 on Wednesday as Arsenal gained revenge on Borussia Dortmund with a fine win in Germany.
Barcelona made it through to the knockout stage for the 10th consecutive season as they beat AC Milan 3-1 at the Camp Nou in Group H in what was the eighth meeting of the clubs in just over two years.
Lionel Messi - who had been criticised in some quarters for not scoring in three games since the 1-1 draw in Milan last month - scored twice for the Catalans, converting a first-half penalty and then combining with Cesc Fabregas to net a superb goal late on.
In between, Sergio Busquets also scored for the hosts while Gerard Pique turned a Kaka cross into his own net to give Milan hope.
"We knew the Messi thing was just a question of games because he is incomparable and in front of goal he is always in form. We hope he now doesn't stop scoring," Busquets told Canal Plus.
"We have achieved our objective. I think we played very well in the first half, it was just a shame to concede the own goal."
The result, combined with Ajax's 1-0 home win against Celtic, means that Barcelona are five points clear at the top of the section and cannot now be denied a place in the top two with two games to come.
Meanwhile, Atletico are through to the knockout stages for the first time since 2008-09 after making it four wins out of four in Group G to guarantee top spot.
Cholo Simeone's side outclassed Austria Vienna, winning 4-0 at the Vicente Calderon with Miranda, Raul Garcia and Filipe Luis scoring in the first half before Diego Costa - who had earlier had a penalty saved - scored his 16th of the season late on.
"It was a good performance and I am pleased that we are through to the last 16," said Simeone. "Now we can relax a little more in the two games we have left against two good sides."
Behind Atletico, Zenit St Petersburg held on to second place by coming from behind to draw 1-1 with 2004 European champions Porto in Russia, Hulk scoring against his former side to cancel out Lucho Gonzalez's opener.
Hulk was a hero and a villain for Zenit, however, as he saw his second-half penalty saved.
Atletico and Barcelona joined Manchester City and defending champions Bayern Munich in qualifying for the last 16 with two group games remaining, but elsewhere Arsenal took a huge step towards the next phase with a fine 1-0 win away to Borussia Dortmund.
The Premier League side gained revenge for a 2-1 defeat when the sides met in London last month, soaking up plenty pressure and snatching a winner when in-form Aaron Ramsey scored his 11th of the season just after the hour mark in Germany.
"It's a difficult place to get a result, but the fans were magnificent," said Ramsey.
"They got behind us and we managed to get the win for them.
"We were very good defensively and we were also very patient. It was a great away performance and a great result."
Arsenal are now level on nine points with Napoli at the top of Group F - with Dortmund three adrift - after the Italians came from behind to beat Marseille 3-2, Gonzalo Higuain scoring twice.
In Group E, Chelsea moved three points clear thanks to a 3-0 win over Schalke at Stamford Bridge, Samuel Eto'o bagging a brace before Demba Ba put the seal on the victory.
"I think it was a good (response), but of course the first 15 minutes were difficult," said Chelsea manager Jose Mourinho.
"We were a team without big maturity and stability after the defeat on Saturday (to Newcastle United in the Premier League). After that, we played very well and kept possession in a comfortable way and after the first goal we played well."
Schalke remain in second spot after Basel were held by Steaua Bucharest, but Chelsea are well placed now to win the group.