Marco Ruben's first-half goal was enough for Villarreal to pull out a 1-0 victory over PAOK Thessaloniki in the Europa League on Thursday.
Villarreal's second victory put it on top of Group D with six points, while PAOK stayed on four points as caretaker coach Makis Havos was unable to break the team out of a slump after Pavlos Dermitzakis left the struggling Greek club after a defeat to Panathinaikos at the weekend.
Dinamo Zagreb also has four points after a 0-0 draw with FC Brugges.
Ruben ran on to a deflected throughball in the 38th minute and unleashed a strong right-footed roller that goalkeeper Dario Kresic got a touch to but couldn't keep out.
"I'm happy since we beat a difficult rival," said Ruben, who has had to come off the bench for most of the season. "The team is playing at an incredible level."
Villarreal dominated possession at El Madrigal Stadium but not chances as Zlatan Muslimovic nearly undid the lead but missed a good scoring chance moments after Ruben's goal.
Vladimir Ivic volleyed a deflected corner kick just over the right corner of Villarreal's goal in the 72nd, while Nabil El Zhar's shot three minutes later missed the same spot.
Dario Kresic got a hand to Ruben "Cani" Garcia's low shot on a break with two minutes to play, but the Greek side did not come close to equalizing after that.
