PARIS: Arsenal remains bottom of Group F in the Champions League but the Gunners finally got their campaign underway with a 2-0 win over Bayern Munich on Tuesday.

After losing both opening matches for the first time, Arsenal desperately needed a win to keep alive its hopes of reaching the knockout round.

Arsene Wenger's men delivered at the Emirates Stadium, ending Bayern's run of 12 straight wins with second-half goals from France striker Olivier Giroud and Germany playmaker Mesut Ozil.

“They dominated the game, but we knew that and we were able to finish it off,” Giroud said.

“We needed this win to stay in the Champions League and to try and qualify for the next stage. We have to thank Petr Cech too, he had a fantastic game.”

Defending champion Barcelona remained in control of top spot in Group E as Ivan Rakitic scored both goals in a 2-0 win at BATE Borisov, while Roma came back from a 2-0 deficit in a 4-4 draw at Bayer Leverkusen in a topsy-turvy game.

In Group G, Chelsea coach Jose Mourinho complained about the referee after the Blues were held to a goalless draw at Dynamo Kiev. Porto tops the standings after a 2-0 defeat of Maccabi Tel-Aviv.

“The referee was weak and naive with the penalty,” said Mourinho after his side was not given a penalty when Cesc Fabregas went down in the area.

“My first thoughts were that it looked like a spot-kick. I cannot understand what the referee behind the goal does, because he doesn't make a clear decision too.”

Here is a look at Tuesday's Champions League matches:

Group E

Neymar continued to lead Barcelona in Lionel Messi's absence with two assists for substitute Ivan Rakitic to score both goals and give Barcelona an easy 2-0 win at BATE Borisov in Belarus.

Coming off his four-goal performance over the weekend, Neymar created a steady stream of scoring chances for the defending European champions.

Rakitic, who went on for the injured Sergi Roberto in the first half, fired in a pinpoint strike from Neymar's pass for Barcelona's first goal in the 48th. Neymar found him a second time in the 64th.

The other Group E match was a wild back-and-forth shootout that ended with Bayer Leverkusen scoring two late goals to grab a 4-4 draw at home to Roma.

Daniele de Rossi scored two goals to cancel out early strikes from Leverkusen's Javier “Chicharito” Hernandez, before Roma took a 4-2 lead with goals from Miralem Pjanic and substitute Iago Falque.

But Kevin Kampl began Leverkusen's comeback in the 84th and substitute Admir Mehmedi scored two minutes later to salvage the draw.

Barcelona has seven points, while Leverkusen remained second with four. BATE has three and Roma two.

Group F

Arsenal revived its hopes of reaching the knockout stages of the Champions League by beating Bayern Munich 2-0.

Olivier Giroud scored in the 77th minute at the Emirates Stadium, bundling the ball into the net after Bayern goalkeeper Manuel Neuer rushed off his line and failed to claim a free-kick from Santi Cazorla.

The ball appeared to come off Giroud's arm last, after first hitting his head as he dived to make contact.

Mesut Ozil scored the second in added time, converting a cross from Hector Bellerin which Neuer pushed out after it had crossed the line.

Elsewhere in the group, Olympiakos won 1-0 at Dinamo Zagreb with a 79th minute goal from Ideye Brown.Bayern and Olympiakos have six points each, three more than Zagreb and Arsenal.

“Everybody can win or lose a game in this group as proved today,” Brown said. “We have to show the same level of attention and dedication in the remaining matches.”

Group G

Chelsea's Champions League campaign hit more trouble in a frustrating 0-0 draw against Dynamo Kiev.

Chelsea dominated the game and was unlucky not to score after hitting the woodwork twice through Eden Hazard and Willian.

On a chilly night in Ukraine, another good chance was missed by Nemanja Matic, who charged through the Dynamo defense but shot wide.

The Ukrainian team came close when Vitaliy Buyalskiy and Derlis Gonzalez forced saves from Chelsea goalkeeper Asmir Begovic, who late on stopped a dangerous attempt by Junior Moraes.

At the halfway point of the group stage, Chelsea is third, one place behind Dynamo.

In Portugal, Vincent Aboubakar and Yacine Brahimi gave Porto a 2-0 win over Maccabi Tel-Aviv and the group lead, with seven points, two more than Dynamo Kiev.

Chelsea has four points, while Maccabi has yet to earn a point.

Group H

Zenit kept its perfect record, making it three victories from three matches with a 3-1 win against Lyon, while Valencia's 2-1 win over Gent in the group's other match lifted the Spanish side five points clear in second place.

Artem Dzyuba scored in the third minute, Hulk fired home a spectacular shot from distance and Danny completed the win as Zenit closed in on qualification for the knockout stage.

Lyon made a dreadful start as Dzyuba found the net for the fifth successive game for Zenit with a clean finish at the far post from Oleg Shatov's pass.

After Alexandre Lacazette canceled out the hosts' lead early in the second half, Hulk stole the ball in midfield, surged toward the goal and unleashed a 30-meter shot into the top corner.

The visitors were then caught on the break after Hulk and Shatov combined well to cut their defense open, with Danny tapping home with a simple finish in the 82nd minute.

Valencia needed two own goals to defeat Gent.

Defender Lasse Nielsen found his own net in the 15th minute before Thomas Foket equalized for the Belgian side in the 40th at Mestalla Stadium.

Stefan Mitrovic added a second own goal in the 72nd to give Valencia its second consecutive win in the competition.

Valencia has six points, three less than Zenit. Lyon and Gent have one point each after three rounds.