Milan, Italy (My Sportsbook) - Ronaldinho converted a penalty in the 35th and AC Milan followed a surprising win in Spain with a 1-1 tie against Real Madrid in the return match at the San Siro on Tuesday in the Champions League.

AC Milan remained atop Group C on the strength of its 3-2 win in Spain, and is followed by Real Madrid, which got its lone goal Tuesday from Karim Benzema, Marseille and Zurich. All four teams remained alive for a spot in the knockout stage in the only group that played Tuesday that still has both spots up for grabs.

Bordeaux secured a spot in Group A with a 2-0 win at Bayern Munich, Manchester United overcame a two-goal deficit to draw CKSA Moscow 3-3 and clinch in Group B, and Chelsea tied Atletico Madrid 2-2 to advance from Group D, along with FC Porto following its 1-0 win over APOEL.

Real was impressive from the opening whistle, creating numerous solid scoring chances in the opening 10 minutes. Benzema, Gonzalo Higuain and Lassana Diarra all forced Dida to make saves before the 10-minute mark,

Dida tried to start a quick counter in the 12th for Milan and picked out Pato, but after he settled outside the area on the right, his cross was wasted when Ronaldinho slipped to the ground and got up asking for a penalty.

Madrid quickly regained control and maintained if for nearly the entire half, and Sergio Ramos was the next to scare Dida with a 19-yard shot inches wide in the 13th.

Higuain followed with a 20-yard blast from the top of the area that sailed too high in the 14th, and Real goalie Iker Casillas followed with his best save of the opening half.

Clarence Seedorf found Pato on the right side of the area and, after he lost Raul Albiol, couldn't sneak a close-range effort past Casillas in the 24th, as the goalie came off his line and deflected the shot.

Madrid solved Dida in the 29th when Kaka fired a 22-yard shot that took a tiny deflection off a Milan player and forced the goalie to dive and knock the ball away from the right post. Benzema was on the loose ball quickly and slotted to the left post, beating Dida with the low shot.

Although Real was in control, Milan got the break it needed six minutes later. Gianluca Zambrotta drove into the left side of the area and tried to cross in, but his pass drilled a sliding Pepe in the back of the arm, and a penalty was awarded by referee Dr. Felix Brych.

Ronaldinho left Casillas no chance, hammering the 12-yard spot kick into the upper left, and Milan was level after 35 minutes.

Pato appeared to hand Milan the lead just a minute later but after winning the ball from Alvaro Arbeloa outside the top of the area and beating Casillas to the bottom left, he was called for a foul on the challenge to erase the goal.

Kaka, who joined Real from AC Milan this summer, followed with Madrid's final scoring chance - Real had 17 shots to just three for Milan in the first half - but Dida made his sixth save of the opening 45 minutes.

After the fast-paced opening half, both sides settled in more after the break. Real and AC Milan struggled to get inside the area, settling for long-range efforts that rarely were on target.

Milan created two of the best chances, the first just before the hour-mark off a free kick to Massimo Ambrosini at the top of the six-yard box. Ambrosini did not judge the ball well, and it sailed just over his head and glanced off his shoulder to waste an open look.

Dida mishandled a corner kick in the 68th, but Milan was lucky no Real players were on the back post.

Veteran Filippo Inzaghi had Milan's last chance in the 83rd, but he could only manage to get the outside of his boot on a cross from Pato, and wasted a great chance from just five yards out.

Raul followed with Real's best scoring chance of the half in the 89th, but his left-footed shot from 10 yards was stopped by Dida, who made his eighth save to cap his strong performance.

Marseille used an early own goal and goals from Fabrice Abriel, Mamadou Niang, Vitorino Hilton, Benoit Cheyrou and Brandao for an easy 6-1 win over Zurich in the other match in Group C.

AC Milan and Real both have seven points, followed by Marseille with six, and Zurich with three.

In Group A, Yoann Gourcuff put Bordeaux into the lead in the 37th and Marouane Chamakh added the clincher in the 90th, and Mauro German Camoranesi scored as Juventus beat Maccabi Haifa 1-0.

In Group B, Paul Scholes scored in the 84th and a 90-minute own goal tied the match in the 90th as Manchester United escaped against CSKA Moscow, and German side Wolfsburg got goals from Zvjezdan Misimovic, Christian Gentner and Edin Dzeko in a 3-0 win over Besiktas.

In Group D, Didier Drogba scored twice in the final 10 minutes, and although a late goal by Sergio Aguero completed his own double, the tie helped Chelsea to clinch advancement, and Radamel Falcao scored in the 84th as FC Porto defeated APOEL.

On Wednesday, Debrecen visits Fiorentina and Liverpool visits Lyon in Group E, Barcelona visits Rubin and Inter Milan visits Dynamo Kyiv in Group F, Rangers visits Unirea and Stuttgart visits Sevilla in Group G, and AZ visits Arsenal and Olympiacos visits Standard Liege in Group H.