Barcelona tops after doubles from Messi and Suarez
Barcelona battered Roma 6-1 at the Nou Camp, with Lionel Messi and Luis Suarez both claiming a brace. Gerard Pique and Adriano also scored, with Neymar missing a penalty but impressing in link play.
Edin Dzeko missed a first-half sitter for Roma, then a late penalty, only to nod home with the game's final act.
Barca's victory secures top spot in Group E, and will leave the rest of Europe on high alert to their chances of going the distance in the tournament.
Earlier, Bayer Leverkusen drew 1-1 at BATE Borisov with Mikhail Gordeichuk giving the home side the lead only for Admir Mehmedi to level for the German side just past the hour mark.
Zenit St Petersburg saw off Valencia 2-0 for their fifth straight European win to guarantee top spot in Group H.
Andre Villas-Boas' men eased home thanks to goals from Oleg Shatov and Artem Dzyuba.
Gent grabbed a last-16 lifeline with a 2-1 victory at Lyon that dumps the French side out of European competition.
Lyon started well with Jordan Ferri putting them ahead after seven minutes, only for Danijel Milicevic to equalise for the visitors with a curling free-kick.
Lyon pressed hard for the winner throughout the second half but Gent stole the points right at the end when Kalifa Coulibaly headed home a corner at the second attempt, some five minutes into stoppage time.
Dynamo Kiev had a surprise 2-0 win at Porto to give themselves a great chance of progressing. Victory moves Kiev to within two points of Porto and Chelsea, and a home win over Maccabi Tel-Aviv would be enough to go through.