AS Roma temporarily moved top of Group G after defeating CSKA Moscow 2-1 in Russia.
Kostas Manolas put the vistors ahead after just four minutes, before Arnór Sigurdsson restored parity six minutes into the second half.
The winning goal arrived eight minutes after CSKA's equaliser, as Lorenzo Pellegrini found the back of the net for the Serie A outfit just three minutes before the hosts had Hördur Magnússon
Valencia registered their first win in Group H after defeating Young Boys 3-1 at the Mestalla.
Santi Mina put the hosts ahead with his first Champions League goal in the 14th minute, but Roger Assalé scored on 37 minutes to level matters.
Mina restored Valencia's advantage just before the halftime break before Carlos Soler rounded off the scoring ten minutes into the second half.