Chelsea and Inter Milan qualified for the last 16 of the Champions League on Tuesday while AC Milan and Barcelona stood on the brink on joining them.
Arsenal, by contrast, stumbled again with a 1-1 home tie with Panathinaikos and has drawn three games in a row.
Kicking off two hours ahead of the rest, Chelsea was first into the last 16 with a 1-0 victory at CSKA Moscow. Inter gained a 0-0 tie with the same Spanish champion Valencia it beat 5-1 two weeks ago but it was enough to reach the next phase.
Despite the point, Valencia is now five points behind Werder Bremen which crushed Anderlecht 5-1 thanks to a hat-trick from Ivan Klasnic and the Spanish titlist is struggling to stay in the competition.
Milan went to Barcelona needing a tie to make sure of reaching the second round but went down 2-1 thanks to late Ronaldinho strike. Now each team has nine points and needs a point from their last two games to reach the second round.
Watched by their Russian owner, Roman Abramovich, Jose Mourinho's Blues made it four wins out of four in Moscow. Dutch winger Arjen Robben finished off a slick interchange with Eidur Gudjohnsen and Damien Duff to score the only goal of the game in the 23rd minute.
CSKA should have leveled just after half time but Vagner Love fired a penalty kick over the crossbar.
"We defended like lions to go home with another clean sheet," said Mourinho, who led FC Porto to the title last season and whose Chelsea has conceded just one goal in its four Group H games. "It was a high intensity match with two teams playing at their highest level."
Mourinho has now gone 15 Champions League games in a row without losing while the club he guided to the title last season, Porto, labored to a 0-0 tie at home to Paris Saint Germain and, with no victory so far and just two points from four games, looks like going out in the first round.
Mourinho's men have drawn level on points with Arsenal in the Premier League and the strain is beginning to tell on the Gunners.
When Thierry Henry stroked home a 16th minute penalty, Arsene Wenger's men appeared in control at Highbury. But Panathinaikos' Angelo Basinas missed a second half penalty and Pascal Cygan, playing instead of the sick Sol Campbell, scored an own goal 16 minutes from the end when he deflected home a speculative shot from Loukas Vintra.
A 10th minute strike by American forward DaMarcus Beasley meant that PSV Eindhoven scored a 1-0 victory over Norway's Rosenborg to keep the Dutch club top of the group by three points.
Andriy Shevchenko gave AC Milan a 17th minute lead in Barcelona only for Cameroon striker Samuel Eto'o to level just before half time. The game was headed for a tie until Ronaldinho hit the winner for runaway Spanish league leader Barcelona with two minutes to go.
Barcelona and Milan have nine points each and Shakhtar Donetsk and Celtic three. Martin O'Neill's men scored a 1-0 victory over the Ukrainian leader which had to play for the last 32 minutes with nine men after two ejections.
Alan Thompson scored the only goal in the 25th minute after French referee Eric Poulat penalized Shakhtar goalkeeper Jan Lastuvka for holding on to the ball for too long with his hands.
Inter Milan's Brazilian striker Adriano was sent off in the final minute for pushing over Valencia's Portuguese defender Marco Caneira in the neck although his team made it to the last 16.