Borussia Dortmund, Southampton and Athletic Club all earned first-leg wins in the third qualifying round but there were problems aplenty for Sampdoria and West Ham.
Southampton, Athletic Club and St-Étienne were among the UEFA Europa League third qualifying round newcomers to impress on Thursday, while Vojvodina and Astra both caused shocks on their travels.
• Second legs: 6 August, Play-off draw: 13.00CET, 7 August
Pick of the action Wolfsberg 0-1 DortmundDortmund's post-Jürgen Klopp era began in Austria but Thomas Tuchel's men were made to work hard for the win. Boasting the likes of Marco Reus, Henrikh Mkhitaryan and İlkay Gündoğan in their starting lineup, it was no surprise to see Jonas Hofmann give BVB a 16th-minute lead after a quick break. The hosts threatened an equaliser, though, Thomas Zündel crashing a great chance over the bar and Roman Bürki making an outstanding late save to deny Tadej Trdina.
Southampton 3-0 VitesseRonald Koeman showed no sympathy for his former club as the Saints manager masterminded a dominant win against the Eredivisie outfit. Graziano Pellè crashed the opener into the roof of the net from the angle on 36 minutes and Dušan Tadić's penalty confirmed the Premier League club's superiority. Substitute Shane Long headed in the third to leave Southampton in a strong position against the club where Koeman began his coaching career.
Athletic Club 2-0 İnter BakıFinalists in 2011/12, Athletic Club's attempt to return to the showpiece began in regulation fashion as debutant Javier Eraso's double sank the Azerbaijani visitors. Lightning wing play on the right from Óscar de Marcos presented the No5 with a simple finish for his opener 12 minutes in and Markel Susaeta's pull-back was fired into the corner by the former Leganés midfielder just after half-time.
Sampdoria 0-4 VojvodinaThe Serbian visitors caused the shock of the night as they swept aside Sampdoria in Italy to plant one foot in the next round. Despite relocating to Turin for the night – rather than their native Genoa – the Serie A men were still expected to have the advantage. Yet Mirko Ivanić slid the visitors into a fourth-minute lead. Aleksandar Stanisavljević followed in Ognjen Ožegović's saved shot to make it two before the latter lobbed in a spectacular third and put things to bed with his second in added time.
West Ham 2-2 AstraAstra's play-off hopes looked dead and buried 51 minutes into the first leg in east London but a late rally earned a draw which leaves the tie on a knife edge. Enner Valencia headed the hosts ahead before Mauro Zárate's close-ranger doubled the lead. The game swung with James Collins' 59th-minute red card, after which Fernando Boldrin pulled one back and Angelo Ogbonna turned into his own net on his Hammers debut.
Tîrgu Mureş 0-3 St-ÉtienneGroup stage participants last term, St-Étienne entered the competition this time with a resounding away win in Romania courtesy of three spectacular strikes from range. Ismaël Diomandé's 25-metre volley opened the scoring for the Verts before Romain Hamouma's first-time curler doubled the advantage. Hamouma rounded things off with a left-footed drive which flew into the corner.
Žilina 2-0 Vorskla PoltavaQualifying top scorer Matej Jelić was at it again as he made it seven goals in five outings. Vasyl Sachko's visitors were behind in the 26th minute thanks to the deadly Croatian forward and Jakub Paur made it two with 17 minutes remaining. To make things worse, the Ukrainian side lost goalkeeper Stanislav Bogush to a late red card and captain Armend Dallku was forced to don the gloves.
Sturm Graz 2-3 Rubin KazanRubin look to have done the hard work in their tie against Sturm after taking a five-goal thriller in Austria. The Russian Premier League outfit twice went ahead only to be pegged back both times, until substitute Igor Portnyagin got the winner in the 61st minute. Sturm's hopes of taking a level scoreline into the away leg ended when 18-year-old Donis Avdijaj picked up a second yellow.
Debrecen 2-3 Rosenborg Tobias Mikkelsen's double helped the visitors to an away win in Hungary but Ádám Bódi's 90th-minute effort for the hosts gave Debrecen hope ahead of next Thursday's return. Elemér Kondás' side went ahead through 19-year-old Norbert Balogh but Mikkelsen and Pål André Helland turned the game on its head in the space of seven second-half minutes. Mikkelsen's second looked to have ended Debrecen ambitions but Bódi's late intervention keeps the tie alive.