Belgian side Genk beat Sassuolo 2-0 on Friday to leapfrog Athletic Bilbao and claim top spot in Group F of the Europa League.
The match was postponed from Thursday because of thick fog.
Brian Heynan put Genk ahead near the hour mark and Leandro Trossard doubled the visitors' lead 10 minutes from time, shortly after Sassuolo's Luca Mazzitelli blasted a long shot off the crossbar.
Genk finished the group stage with 12 points, two more than Athletic, who also advanced to the round of 32.
Sassuolo recorded their first win in seven Serie A matches as two penalties before the break set them on their way to a 3-0 home victory over Empoli.
Lorenzo Pellegrini opened the scoring from the spot in the 22nd minute after Lukasz Skorupski's foul on Antonino Ragusa.
Federico Ricci then also made a successful conversion from 12 yards following a handball in the area by Daniele Croce.
Ragusa subsequently extended his side's lead with a close-range strike eight minutes into the second half.
Gregoire Defrel's stunning equaliser snapped Sassuolo's losing streak and handed Napoli's Serie A title hopes another blow.
Defrel's late volley cancelled out Lorenzo Insigne's opener as Napoli were held to a 1-1 draw - their third stalemate in a row at the Stadio San Paolo in all competitions.
Leaders Juventus lost on Sunday, while the rest of the top six won, leaving Napoli down in seventh, eight points behind the reigning champions.
Insigne had a couple of sights at goal in the first half. First...