ROME (AP) -- Lionel Messi had a pair of goals that ended a rare three-game scoreless streak, and Barcelona beat AC Milan 3-1 Wednesday night to clinch a berth in the second round of the Champions League.
Messi converted a 30th-minute penalty kick for his first goal at the Camp Nou since Sept. 24, and Sergio Busquets doubled the lead with an angled header nine minutes later.
Barcelona defender Gerard Pique redirected Kaka's cross into his own goal in the 45th, but Messi scored off a pass from Cesc Fabregas in the 83rd. Messi, who has struggled with a leg injury, has 65 Champions League goals and is six shy of Raul Gonzalez's record.
''Leo played a phenomenal game,'' Barcelona coach Gerardo Martino said. ''He was sharp, showed quickness and was better one on one.''
Barcelona (3-0-1) leads Group H with 10 points, followed by Milan (1-1-2) with five, Ajax (1-2-1) with four and Glasgow Celtic (1-3) with three. Ajax beat visiting Celtic 1-0 in Lasse Schoene's 51st-minute goal.
''I'm not sure what will happen with my future,'' Milan coach Massimiliano Allegri said. ''We have to win our next league game and there is still much to play for in the Champions League.''
Atletico Madrid (4-0) also advanced, clinching first place in Grouo G by winning 4-0 at home against Austria Vienna (0-3-1) on goals by Miranda, Raul Garcia, Filipe Luis and Diego Costa. Zenit St. Petersburg (1-1-2) is second with five points after a 1-1 tie against visiting Porto (1-2-1). Lucho Gonzalez gave Porto the lead by heading in Danilo's cross in the 23rd minute, and Hulk tied it five minutes later against his former club. Helton saved Hulk's 52nd-minute penalty kick.
Group F leader Arsenal (3-1) won 1-0 at third-place Borussia Dortmund (2-2), taking the lead in the 62nd minute when Aaron Ramsey scored on the Gunners' first shot on goal.
''Once we were in the lead, we were not so much under pressure,'' Arsenal manager Arsene Wenger said.
Napoli (3-1) is second following a 3-2 home win against Marseille (0-4), which was eliminated. After Andre Ayew put the visitors ahead in the 10th minute, Gokhan Inler tied the score with a volley in the 22nd minute and Gonzalo Higuain put the hosts ahead in the 24th. Florian Thauvin tied the score in the 64th, and Higuain restored Napoli's lead in the 75th. Before kickoff, a bus carrying Marseille supporters was damaged during clashes involving fans.
Group E leader Chelsea (3-1) won 3-0 over visiting Schalke (2-2) on two goals by Samuel Eto'o, who scored for his fourth team in the Champions League, and one by Demba Ba. Eto'o put the Blues ahead following a failed clearance by Schalke goalkeeper Timo Hildebrand. A Julian Draxler shot off a pass from American midfielder Jermaine Jones was turned wide by Chelsea goalkeeper Petr Cech.
Eto'o was acquired in August from the Russian club Anzhi Makhachkala.
''He was for two years playing without big motivations and when you play without big motivations ... you lose condition, you lose sharpness and you even lose appetite,'' Chelsea manager Jose Mourinho said. ''So it wasn't a surprise to me he arrived here not in the best condition after two years in Anzhi.''
Basel (1-1-2) tied 1-1 at home against Steaua Bucharest (0-2-2) on a second-half, stoppage-time goal by Giovanni Sio. Federico Piovaccari scored in the 17th for Steaua.
Sunderland will play Chelsea in the English League Cup quarterfinals after beating Premier League rival Southampton 2-1.
Phil Bardsley put host Sunderland in front in the 59th minute after goalkeeper Kelvin Davis parried Jozy Altidore's header, and Sebastian Larsson made it 2-0 in the 86th. Defender Maya Yoshida scored two minutes later for Southampton.
In the other quarterfinals next month, Manchester United plays Stoke, Manchester City is at Leicester and Tottenham faces West Ham.