Celtic and AC Milan took their places in the last 16 of the Champions League despite vastly contrasting fortunes on Tuesday.
Celtic celebrated one of the best nights in their long history of European competition by beating English rivals Manchester United 1-0 in Glasgow to ensure first or second place in Group F and a berth in the knockout stage for the first time.
Shunsuke Nakamura scored the only goal of the game with a free kick eight minutes from time, while Celtic goalkeeper Artur Boruc joined him on the hero's rostrum by saving Louis Saha's weakly-taken 90th minute penalty.
Manchester United would have advanced with a win or draw at Celtic, but they now have to avoid defeat at home to Benfica in their last match on Dec. 6 to ensure they do.
Celtic top the group with nine points, followed by United (9), Benfica (7) and FC Copenhagen (4). Benfica beat Copenhagen 3-1 in the other game in the group.
While Celtic were rejoicing, AC Milan lost 1-0 at AEK Athens, who have now won their last two matches after establishing an unenviable record of 21 games without a victory in the competition.
Julio Cesar scored the only goal from a free kick after 32 minutes but despite the defeat Milan cannot finish out of the top two places in Group H.
Although they advanced with a defeat, defender Alessandro Costacurta had a night to remember as he became the oldest player to appear in the Champions League aged 40 years 211 days.
The Italians go into the last 16 along with Celtic and previously qualified Bayern Munich, Liverpool, Olympique Lyon, Real Madrid, PSV Eindhoven and Valencia.
Milan have 10 points followed by AEK (7), Lille (6) and Anderlecht (3).
CSKA Moscow and Lille could also have clinched their places in the last 16 but results went against them andprevented them from doing so.
In Group G, CSKA lost 2-0 at home to Porto who won with goals from Ricardo Quaresma and Lucho Gonzalez.
That setback, together with Arsenal's 3-1 comeback win over Hamburg SV in the same group, meant CSKA slipped from first to third in the standings behind Arsenal and Porto.
Arsenal have 10 points, Porto are also on 10, CSKA have eight and Hamburg none.
Arsenal made hard work of beating the bottom team in the group though, with the Germans taking the lead when Rafael van der Vaart scored with a superb shot after four minutes.
It took Arsenal until the 52nd minute to equalise through Robin van Persie before Emmanuel Eboue and Julio Baptista added two more for the Gunners in the last seven minutes.
However, Arsenal will be without Thierry Henry for the match in Porto after he picked up his third booking of the competition and now faces a one-match ban.
Lille could have advanced with Milan from Group H but after being held to a 2-2 draw at home by Anderlecht they now face an uphill task in their last match at Milan.
In Group E, Steaua Bucharest's 1-1 draw with Dynamo Kiev means the Romanian side qualify for a UEFA Cup place while Dynamo are eliminated from Europe.
Real Madrid's 2-2 home draw with Olympique Lyon in the same group ensures the French champions finish top although both teams knew they had already qualified after the last round.
Lyon have 13 points, Real 10, Steaua four and Dynamo one.
Real became the first team to breach the Lyon defence in the competition this season but could have inflicted a first defeat if Ruud van Nistelrooy, who got Real's second in the 83rd, had not had his 89th minute penalty saved by Gregory Coupet.
Matchday Five continues on Wednesday with games in Groups A-D.