Athletic Bilbao edge through
Last season's beaten Europa League finalists Athletic Bilbao were made to work hard by Slaven Belupo before edging through 4-3 on aggregate.
Bilbao, beaten in last season's final by fellow Spanish side Atletico Madrid, had led 3-1 from the third qualifying round first leg but twice went behind in the city of Koprivnica.
The Croatians took the lead after 28 minutes through defender Alen Maras but Iker Muniain gave Bilbao some breathing space when he scored the equaliser two minutes into the second half.
However, a second goal for the home side by Mario Gregurina with 21 minutes to go made for an uncomfortable end to the game for the Spanish side.
Danish side AC Horsens shocked Swedish rivals Elfsborg with an aggregate 4-3 win after winning the second leg 3-2 in Boras.
With the tie 1-1 after the first leg it was the visitors who took the lead after three minutes through Lasse Jorgensen but three minutes later Lasse Nilsson had levelled the game up.
Thomas Kortegaard put the visitors back in front after 13 minutes but five minutes later David Elm had got Elfsborg a second equaliser.
But nine minutes before half-time Kortegaard got his second which proved decisive for Horsens.
Belgian side Racing Genk went through 4-2 on aggregate after a 2-1 win away to Aktobe Lento.
Crvena Zvezda scraped through 6-5 on penalties against Omonia Nicosia in Cyprus after the game had finished 0-0 after extra-time, the same score as in the first leg in Belgrade.
APOEL Nicosia, who made history last season when they became the first Cypriot side to reach the quarter-finals of the Champions League, defeated Aalesund 1-0 to complete a 3-1 aggregate win.
Legia Warsaw overturned a 2-1 first leg deficit to SV Reid with a 3-1 victory in Poland, Marek Saganowski, Miroslav Radovic and Danijel Ljuboja were on target before Robert Zulj got a consolation for the visitors.
Aleksander Prijovic scored as early as the ninth minute as Tromso won 1-0 away to Metallurg Donetsk to triumph 2-1 on aggregate.
FC Twente completed a comfortable success against Mlada Boleslav as a 2-0 win matched the first leg scoreline and Rosenborg had their away goal from the first leg to thank for their progress as they were held 0-0 at home by Servette.
Goals from Emmanuel Mayuka, Mario Raimondi and Raul Marcelo Bobadilla earned Young Boys a 3-1 aggregate victory against Kalmar.
Steaua Bururesti overturned a 1-0 deficit by defeating Spartak Trnava 3-0 and Videoton beat Gent 3-0 to make it 4-0 overall.
Inter Milan survived a scare against Hajduk Split to squeeze through 3-2 on aggregate against the Croatian side.
Inter led 3-0 from the first leg and would have hoped for a comfortable passage to the next round.
But a penalty from Ante Vukusic after 23 minutes and Ivan Vukovic's goal with 58 minutes gone made for a nervous last half hour for the Serie A side.
The tie between Cypriot outfit Anorthosis Famagusta and Georgian visitors Dila Gori had to be abandoned with seven minutes to go.
The home side had won the first leg 1-0 in Georgia but after the visitors had gone 3-0 up in Thursday night's second leg the referee was forced to abandon the game because of crowd trouble.
Samuel Eto'o scored both goals, the second a penalty, as Anzhi Makhachkala won 2-0 against Vitesse Arnhem to complete a 4-0 aggregate win.
Marseille went through 4-1 on aggregate against Eskisehirspor after a 3-0 second leg success.
Lech Poznan had a consolation 1-0 win over AIK after losing the first leg 3-0 and Arsenal Kiev made it 5-0 against Mura with a 2-0 second leg victory.
PAOK Salonika beat Bnei Yehuda 4-1 to progress 6-1.
Michal Duris netted a first half hat-trick as Viktoria Plzen thrashed Ruch Chorzow 5-0 to win 7-0 overall.
Bursaspor overcame a 1-0 first leg defeat with an emphatic 6-0 victory against KuPS Kuopio and an away goal from a first leg 2-1 defeat took Zeta through as they beat FK Sarajevo 1-0.
Sparta Prague drew 2-2 with Trenkwalder Admira to triumph 4-2 and Heerenveen went through 4-1 despite losing 1-0 tonight away to Rapid Bucuresti.
Maritimo progressed on away goals after a 0-0 draw with Asteras Tripoli followed a 1-1 scoreline in the first leg.
Rapid Vienna overturned a 2-1 first leg deficit to go through after a 2-0 home win over Vojvodina.