Denis Suarez's brilliant late free-kick gave Villarreal a narrow lead to take to Italy in their Europa League last-32 tie with Napoli.
Jurgen Klopp's homecoming did not go exactly to plan as his Liverpool side were held to a goalless draw against Augsburg in Germany.
Manchester United have been drawn against Danish champions Midtjylland in the Europa League round of 32, while Liverpool will play Augsburg.
Borussia Dortmund face a difficult draw for the Europa League round of 32 and could face the likes of Manchester United - or Jurgen Klopp's Liverpool - after losing 1-0 at home to PAOK and finishing as runners-up in Group C.
Celtic's Europa League hopes were ended for the season as Ajax substitute Vaclav Cerny scored a late winner for the visitors at Parkhead.
Christian Benteke's brilliant strike saw Liverpool beat Bordeaux 2-1 to qualify for the knockout stages of the Europa League with a match to spare.
Borussia Dortmund conceded a penalty in the first minute and ceded top spot in their Europa League group to opponents Krasnodar with a 1-0 defeat on Thursday.
Harry Kane fired Tottenham into the knockout stages of the Europa League as they finally overcame stubborn Group J minnows Qarabag 1-0 in Baku.
Jurgen Klopp is starting to build some momentum at Liverpool after a third successive victory - the club's first away from home in Europe for nearly three years.
Mousa Dembele scored a stunning late winner as Tottenham beat Anderlecht 2-1 to move top of Group J in the Europa League.
Borussia Dortmund secured their place in the knockout stage after routing Azerbaijan side Qabala 4-0 in Group C.
Stefano Okaka scored and Anderlecht rallied to hand Tottenham a 2-1 defeat in the Europa League on Thursday.
Liverpool settled for a 1-1 draw at Anfield against Swiss side FC Sion in the Europa League on Thursday.
Liverpool manager Brendan Rodgers' Europa League gamble almost paid off as the club's young guns were held to a 1-1 draw in Bordeaux.
Son Heung-Min scored a quick-fire brace on his home debut as Tottenham came from behind to beat Qarabag in their Europa League opener on Thursday night.
Basel took revenge on Paulo Sousa, as Fiorentina fumbled a lead to lose 2-1 at home with Gonzalo Rodriguez sent off.
Napoli started the Europa League in style, demolishing Club Brugge 5-0 with Jose Callejon and Dries Mertens braces.
Park Joo-Ho headed a last-gasp winner as Borussia Dortmund came from behind to launch their Europa League campaign with a 2-1 win over Krasnodar.
A late goal from substitute Lasse Schone gave Ajax a 2-2 draw against Celtic at the Amsterdam ArenA where Hoops left-back Emilio Izaguirre was sent off.
Tottenham Hotspur have been handed a tough draw in the group stage of the Europa League.
Thomas Tuchel pronounced himself "generally happy" after his Borussia Dortmund side crushed Odds BK 7-2 in their Europa League qualifier second leg on Thursday.
Southampton were sent crashing out of Europe on Thursday evening courtesy of a strike from FC Midtjylland's very own "Big Dunc."
Borussia Dortmund rallied from a shocking three-goal deficit to win 4-3 at Odd Grenland in the Europa League playoff round first leg on Thursday.
Borussia Dortmund have been handed a tie with Odd in their Europa League playoff, while Southampton are set to face Midtjylland.
West Ham were eliminated from the Europa League on Thursday after losing 2-1 to FC Astra in Romania.
Borussia Dortmund began their Europa League campaign with a 1-0 win away to Wolfsberger AC on Thursday.
West Ham were made to sweat on their Europa League future as they were taken to penalties in the second qualifying round against Maltese minnows Birkirkara.
Colombian striker Carlos Bacca claimed a double as Sevilla made Europa League history by seeing off Dnipro to win the competition for a record fourth time.
Sevilla can tonight become the first side to win four Europa League or UEFA Cup titles when the holders face unfancied Ukrainians Dnipro in Warsaw.
Dnipro advanced to their first European final after Yevhen Seleznyov's second-half header gave them a 2-1 aggregate win over Napoli in the Europa League.
Alexandre Lacazette's first-half goal gave Arsenal a 1-0 win over FK Qarabag in Europa League Group E action on Thursday.
Olympiakos pulled off a stunning 3-1 Europa League win over AC Milan that put them into the round of 32 and sent the Italians crashing out as the remaining places in the knockout stage were decided on Thursday.
Table-toppers Chelsea drew 2-2 at Vidi in their final Group L in the Europa League on Thursday.
Chelsea made it five wins in five tries in the Europa League with a convincing 4-0 win against 10-man PAOK at Stamford Bridge on Thursday.
Arsenal maintained their three-point lead atop Europa League Group E on Thursday with a 3-0 win against Vorskla.
AC Milan came from behind before stepping on the gas to pull away from F91 Dudelange for a 5-2 Europa League win on Thursday.
Arsenal qualified for the Europa League knockout stage with a 0-0 draw against Sporting at The Emirates, although striker Danny Welbeck was carried off on a stretcher in the first half with a serious ankle injury.
AC Milan and Real Betis took a step towards qualifying for the Europa League knockout stage with a 1-1 draw in Group F on Thursday.
Olivier Giroud ended his drought by scoring the only goal as Chelsea won 1-0 at BATE Borisov on Thursday to clinch a place in the knockout stage of the Europa League with two group games to spare.
Arsenal and Chelsea were among seven teams to reach the Europa League knockout stage on Thursday, while last year's runners-up Olympique de Marseille were eliminated at the group phase.
Ruben Loftus-Cheek scored three goals as Chelsea dispatched BATE Borisov 3-1 in Europa League action on Thursday.
Real Betis stunned AC Milan with a 2-1 win at the San Siro in Europa League group play on Thursday.
Danny Welbeck's goal in the 77th minute was enough for Arsenal to get a 1-0 win over Sporting CP in Europa League action on Thursday.
Sevilla suffered a shock defeat by Russians Krasnodar, going down 2-1 in Europa League Group J.
Ten-man Celtic threw away an early lead to succumb to a 3-1 defeat to Red Bull Salzburg in Austria.
Alvaro Morata provided the lone goal in Chelsea's 1-0 win over Vidi in Europa League group-stage action on Thursday.
Emile Smith Rowe scored his first career goal in Arsenal's 3-0 win over FK Qarabag in Europa League group-stage action on Thursday.
Substitute Patrick Cutrone netted twice in nine minutes to lift AC Milan to a 3-1 comeback win at home to Olympiakos in Europa League group-stage action.
Arsenal's superb form continued into the Europa League as they thrashed Ukrainian side Vorksla Poltava 4-2 on Thursday.
Gonzalo Higuain's deflected effort in the 59th minute sealed a 1-0 victory for AC Milan over Luxembourg side F91 Dudelange on Thursday night in Europa League action.
Chelsea's Europa League campaign kicked off in style with a 1-0 win at PAOK Salonika on Thursday.
Leigh Griffiths made the difference for Celtic in their Europa League opener, coming off the bench to score a late winner against Rosenborg.
Burnley's European adventure came to an end on Friday as the Premier League side crashed out of the Europa League playoff round with a 1-1 draw against Olympiakos.
Celtic were held to a 1-1 draw by Lithuanian side Suduva Marijampole in the first leg of their Europa League play-off at the ARVI Futbolo Arena.
Antoine Griezmann struck twice as Atletico Madrid powered past Marseille to lift their third Europa League title in nine years.
Atletico Madrid advanced to the Europe League final 2-1 on aggregate after a 1-0 victory over Arsenal at the Wanda Metropolitano on Thursday.
Marseille scored a dramatic extra-time decider against Red Bull Salzburg to earn a Europa League final showdown with Atletico Madrid in Lyon on May 16.
If Arsene Wenger's Arsenal finale is to be a Europa League final in Lyon his side will have to do it the hard way after surrendering a well-deserved lead to draw against 10-man Atletico Madrid in the first leg of their semi-final.
Florian Thauvin put Marseille within touching distance of a place in the UEFA Europa League final with a controversial opener as his side beat Red Bull Salzburg 2-0 at the Stade Velodrome.
Arsenal will face Atletico Madrid later this month in their first appearance in the Europa League semifinals since 2000.