Barcelona were held to a draw 1-1 draw at Roma as they got their Champions League defence under way on Wednesday night.
Luis Suarez gave Barca a 21st-minute lead in the Group E contest but Roma equalised 10 minutes later with a wonder goal from defender Alessandro Florenzi.
Florenzi drilled a right-footed shot from just over the halfway line and the ball cannoned into the back of the net off a post.
Elsewhere in the pool, Hakan Calhanoglu scored a brace either side of Javier Hernandez's first goal for Bayer Leverkusen as the German side saw off BATE Borisov 4-1 at home.
Leverkusen took the lead in the fourth minute through a delightful Admir Mehmedi effort, only for their Belarusian opponents to draw level nine minutes later via Nemanja Milunovic's deflected header.
The hosts went back in front two minutes into the second half when Calhanoglu's shot diverted in off Dzyanis Palyakow.
Hernandez, signed last month from Manchester United, then marked his first Leverkusen start with a tidy right-footed finish in the 59th minute, before Calhanoglu converted a 75th-minute penalty.
Thomas Muller’s scoring hot-streak continued as he netted a brace to steer Bayern Munich to a 3-0 win at Olympiacos.
Muller put the Bayern ahead in the 52nd minute with a lofted effort from outside the box which looked as if it had been intended as a cross.
Substitute Mario Gotze then lashed in with a minute of normal time remaining, before Muller converted a penalty in stoppage time to take his tally for the season to eight Bayern goals and 11 overall, including those scored for Germany.
Meanwhile, Group F rivals Arsenal had striker Olivier Giroud sent off as they slumped to a disappointing 2-1 defeat at Dinamo Zagreb.
Dinamo took the lead against the run of play with an own-goal from Alex Oxlade-Chamberlain and after Giroud's dismissal on 40 minutes for a second bookable offence, the hosts doubled their lead through a powerful header by Junior Fernandes.
Despite a late goal from substitute Theo Walcott, Arsenal were left to reflect on another frustrating European away performance.
Chelsea had a far better time of it in Group G as they thumped Maccabi Tel Aviv 4-0 at Stamford Bridge.
Willian, Oscar, with a penalty, Diego Costa - on as a substitute after being omitted as one of six changes following the loss at Everton - and Cesc Fabregas scored as the Blues returned to winning ways.
Eden Hazard missed an early spot-kick at 0-0 but it mattered little come the final whistle.
