Bayer Leverkusen staged a dramatic second half comeback to beat Valencia 2-1 in Germany and do themselves a huge favour in their battle to reach the knockout stages alongside likely Group E qualifiers Chelsea.
Brazilian Jonas gave the Spaniards a 24th minute lead but two goals in four second half minutes from Andre Schurrle and Sidney Sam gave Leverkusen the win.
They are now four points clear in second place.
Olympiakos claimed their first points in Group F with a 3-1 win over Borussia Dortmund in Greece.
Rafik Djebbour and Francois Modesto earned the points for the home side after Jose Holebas' eighth minute opener had been cancelled out midway through the first half by Dortmund's Robert Lewandowski.
Milan and Barcelona made qualification from Group H appear a mere formality as both continental giants recorded straight-forward home wins over BATE Borisov and Viktoria Plzen respectively.
In Italy, Milan were never troubled by the Ukrainians with Zlatan Ibrahimovic opening the scoring after 33 minutes and Kevin Prince Boateng making it 2-0 with 20 minutes to play.
Defending champions Barcelona kept pace with an equally assured win over the outclassed Plzen, Andres Iniesta opening the scoring on 10 and David Villa rounding things off eight minutes from time.
In Group G, surprise package APOEL continue to set the pace after holding out for a 1-1 draw away to Porto. Hulk gave the home side a 13th minute lead but Brazilian Ailton Almeida equalised six minutes later.
APOEL stay top because Shakhtar Donetsk and Zenit St Petersburg could not be separated in Ukraine. Shakhtar twice led through Willian and Luiz Adriano, but were pegged back by goals from Roman Shirokov and Viktor Faizulin.