The 2017-18 Champions League group stage began on Tuesday, with eight matches being played as four groups got underway. Here's everything you need to know:

Final scores

Roma 0, Atletico Madrid 0
Chelsea 6, Qarabag 0
Sporting Lisbon 3, Olympiacos 2
Barcelona 3, Juventus 0
Paris Saint-Germain 5, Celtic 0
Bayern Munich 3, Anderlecht 0
Manchester United 3, Basel 0
CSKA Moscow 2, Benfica 1

Standings

Check out standings page here. 

Messi finally gets one (make it two) past Buffon

In 180-plus minutes last season in the Champions League, Lionel Messi and his Barcelona teammates had a difficult time finding the back of the net and scoring against Gianluigi Buffon and Juventus. However, in the group stage opener at Camp Nou, Leo was back to his normal, dominant self and made the Italians pay during Tuesday's 3-0 thrashing of Juventus. Messi scored the opener for Barcelona just before the end of the first half, megging his defender in the process and leaving Juve goalkeeper Gianluigi Buffon frozen, marking his first career goal on the Italian legend. Take a look:

Golazo. What a lovely low hit, and Buffon just stood there like a statue, knowing nothing could be done. These two faced each other on four separate occasions, Messi had gone 315 minutes without finding the back of the net against Buffon. He ended up getting two on the day. The drought is finally over and another keeper is crossed off Messi's list.   

Neymar, Mbappe score in their UCL debut for PSG

Neymar and Kylian Mbappe both scored in their Ligue 1 debut for PSG, and they've done it again in the Champions League on Tuesday. Neymar, the world's most expensive player opened the scoring for the Parisians in a 5-0 rout over Celtic in Scotland, using his blazing speed early on to get behind the back line and finishing with class. Take a look:

Newboy Mbappe, who joined from Monaco this month, also got in on the scoring moments later, giving PSG a 2-0 advantage.

Boy, folks better get used to these two as PSG has lofty expectations this season after a busy transfer window.

Chelsea rolled big time and got goal of the day

The Blues were playing a team -- from Azerbaijan -- you probably have never heard of in Qarabag, but you can't ignore a 6-0 result. The Blues were expected to roll, and they took care of business with five different players scoring, including Davide Zappacosta on his full debut. Take a look at his strike, which very well could be the goal of the day:

Pogba injured

Manchester United star Paul Pogba picked up a hamstring injury and was taken off just after the hour mark. United fans will be content with the result but uneasy until his status is known. The creative engine for the Red Devils, we'll have to await details and confirmation from the club. The fact that he was able to walk off under his own power is encouraging, but he could miss a bit of time, and if he does, United is in trouble.

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