PARIS (AFP) AC Milan and Marseille reached the Champions League last 16 on Tuesday, but Arsenals hopes of joining them are in the balance following a shock defeat at Sporting Braga. Seven-time champions Milan were made to work hard before emerging from their trip to Auxerre with a 2-0 victory that secured second place in Group G behind Real Madrid. The French side had procured all the clear-cut chances until Zlatan Ibrahimovic blasted Milan ahead in the 64th minute, with substitute Ronaldinho curling home in injury time to complete the victory. We were under heavy pressure at the start of the match and we felt a little bit trapped inside our penalty area, but everything finished well, said Milan coach Massimiliano Allegri. Real made sure of top spot in the group and continued their unbeaten record in this seasons competition by thrashing Ajax 4-0 in Amsterdam. Karim Benzema broke the deadlock by side-footing into the roof of the net in the 36th minute, with full-back Alvaro Arbeloa doubling the Spanish sides lead with a long-range rocket just before half-time. A second-half brace from Cristiano Ronaldo, the second a penalty, set the seal on a comfortable victory, but Real had Xabi Alonso and Sergio Ramos sent off for two bookable offences late on. Both players received their second cautions for time-wasting and will now miss Reals final group game at home to Ajax. French champions Marseille had earlier secured their place in the knockout round with an impressive 3-0 win at Spartak Moscow. Beaten 1-0 in the reverse fixture in September, Marseille had to win to make sure of second place in Group F and they assumed control of proceedings in the 18th minute through a smart turn and finish by Mathieu Valbuena. Valbuenas France international colleague Loic Remy made it 2-0 nine minutes into the second half, before Brandao fired into the bottom-right corner to rubber-stamp Marseilles progress. Spartak saw Brazilian striker Welliton dismissed between Marseilles second and third goals after an altercation with OM centre-back Souleymane Diawara. It is important for the club, said Marseille coach Didier Deschamps. I am a very, very satisfied coach this evening, both with how we played and the result. In the other group fixture, a youthful Chelsea side came from a goal down to win 2-1 at home to Slovakians MSK Zilina and preserve their 100 percent record in this seasons competition. Two late goals from Matheus saw Arsenal slump to a 2-0 defeat at Braga that means Arsene Wengers side must beat Partizan Belgrade in their final group match to be sure of reaching the next stage. Arsenal had a strong penalty appeal turned down after Carlos Vela went down in the penalty area under a challenge by Alberto Rodriguez and within minutes Mateus had scampered through to put the hosts ahead. The Brazilian striker crashed home his second in injury time, and Arsenals disappointment was compounded by the sight of captain Cesc Fabregas limping off with an apparent hamstring injury. What is the fifth official doing if he cant see that? said Wenger of the penalty incident. Its an absolutely useless system. Other than that, it was a difficult game against a team that used all the tricks to slow the game down. Shakhtar Donetsk won 3-0 at Partizan and are now virtually assured of a place in the next phase. Roma produced the performance of the night to come back from 2-0 down to beat last seasons beaten finalists Bayern Munich 3-2 at Stadio Olimpico. Two goals from in-form Mario Gomez had put Bayern on course for victory, but well-worked strikes by Marco Borriello and Daniele De Rossi drew Roma level before Francesco Totti netted the winner with an 84th-minute penalty. It wasnt easy, especially in the first half, but the players were magnificent, beamed Roma coach Claudio Ranieri. Roma now trail already-qualified Bayern by three points in Group E and will progress if they avoid defeat at CFR Cluj, who lost 1-0 at Basel, in their final group game. Ronaldo scores double as Real outclass Ajax A double from Cristiano Ronaldo formed the centrepiece of a masterclass by Real Madrid here on Tuesday as they eased to a 4-0 away win over Dutch side Ajax in their Champions League Group G clash. The Portuguese star scored twice in the second-half after first-half goals by Karim Benzema and a stunning effort by Alvaro Arbeloa had put them in cruise control mode - the only blot on their evening were two late sendings off of World Cup winning duo Xabi Alonso and Sergi Ramos. Ajax coach Martin Jol had gone for broke in his line-up with three strikers - including Uruguayan Luis Suarez despite his being punished by the club for a biting incident at the weekend - and two attacking midfielders. Jol probably hoped Jose Mourinho would use the match to try some of his second choice players but the Portuguese maestro resisted the urge and injured players apart it was a first choice team that kicked-off. Benzema - who showed his class with a goal against England in the friendly victory last week - shot home from just inside the area after Mesut Ozil had defly knocked back with his heel Alonsos perceptive long pass. Ajax had little bit in attack as Suarez was swamped whenever he got a sniff of the ball and it was no surprise when the visitors struck again shortly before half-time. Ronaldos freekick rebounded off the wall but Arbeloa had no hesitation in trying his luck from way outside the area and his swerving effort left hosts 'keeper Maarten Stekelenburg rooted to his line. Ronaldo should have made it 3-0 in the 47th minute as Benzema found him and he twisted free of his marker to be one on one with Stekelenburg but the Dutch 'keeper somehow managed to get down and deflect the shot over the bar leaving the Portuguese superstar shaking his head in disbelief. He was not to be denied in the 70th minute, though, as set up by Argentinean substitute Angel di Maria he made no mistake as he shot past Stekelenburg and 10 minutes later he converted a penalty.