A coveted group stage place awaits the ten winners as the play-offs begin on Tuesday with PSV Eindhoven v AC Milan among the highlights. UEFA.com picks some first-leg facts.
FC Shakhter Karagandy v Celtic FC
• This is the first meeting at either club or national-team level between sides from Kazakhstan and Scotland, and the first time Shakhter have faced a team of European trophy-winning pedigree.
• While Kazakhstan is the 36th different country for Scottish champions Celtic to visit for a UEFA competition fixture, Shakhter have only a short European history, their first taste of continental competition coming in the UEFA Intertoto Cup in 2006.
Olympique Lyonnais v Real Sociedad de Fútbol
• The San Sebastian club have not featured in Europe since losing 2-0 on aggregate to Lyon in the 2003/04 UEFA Champions League round of 16.
• During their 2012/13 UEFA Europa League run, Lyon got the better of Real Sociedad's Basque rivals Athletic Club in the group stage, winning 2-1 at home and 3-2 away.
FC Paços de Ferreira v FC Zenit St Petersburg
• Zenit have never won in Portugal and lost their two previous two-legged contests with Liga opposition. They went down 5-4 on aggregate to CD Nacional in a 2009/10 UEFA Europa League play-off and fell 4-3 to SL Benfica in the 2011/12 UEFA Champions League round of 16.
• Paços made their European debut in the 2007/08 UEFA Cup first round, losing 1-0 on aggregate to AZ Alkmaar. Their solitary goal came in UEFA Europa League qualifying in 2009/10 as they overcame FC Zimbru Chisinau 1-0 over two legs, but then succumbed 2-0 overall to Bnei Yehuda Tel-Aviv FC in the third qualifying round.
PSV Eindhoven v AC Milan
• Milan prevailed on away goals against PSV after a 3-3 aggregate draw in the 2004/05 semi-finals. Carlo Ancelotti's side won the first leg 2-0 through strikes by Andriy Shevchenko (42) and Jon Dahl Tomasson (90). Park Ji-Sung (9) – now back at PSV on loan – and Phillip Cocu (65) levelled the aggregate score in the second leg, but Massimo Ambrosini's added-time effort took the Rossoneri through, despite Cocu then adding a third for Guus Hiddink's PSV.
• Now PSV coach, Cocu also played both matches when the clubs met again in the next season's group stage, the Eredivisie outfit drawing 0-0 away and then winning 1-0 at home – Jefferson Farfán (84) scored while Milan's former PSV defender Jaap Stam was sent off.
FC Viktoria Plzeň v NK Maribor
• Plzeň have won all ten of their UEFA Champions League qualifiers, in 2011/12 and this season, scoring 34 goals in the process.
• For Maribor, this is the 11th time they have entered UEFA Champions League qualifying but only once before have they won through to the group stage – in 1999/2000.
GNK Dinamo Zagreb v FK Austria Wien
• Dinamo's recent home record in qualifiers is formidable. Including this season's 1-0 victories over CS Fola Esch and FC Sheriff, they have posted eight successive wins.
• The visitors' only previous tie against Croatian opposition was a 2-2 aggregate draw with HNK Hajduk Split in the 1977/78 European Cup Winners' Cup quarter-finals. Austria won on penalties.
PFC Ludogorets Razgrad v FC Basel 1893
• The Bulgarian title holders had only played one European tie before this season – losing to a GNK Dinamo Zagreb goal eight minutes into added time in last term's second qualifying round just as an away-goals triumph beckoned.
• Basel's only previous meeting with Bulgarian opposition came in the 2009/10 UEFA Europa League group stage when they took on PFC CSKA Sofia, triumphing 2-0 at the same venue where they now face Ludogorets, the Natsionalen Stadion Vasil Levski, and 3-1 at home.
FC Steaua Bucureşti v Legia Warszawa
• Steaua's only previous two-legged contest with a Polish side came against Zagłębie Lubin in the 2007/08 UEFA Champions League second qualifying round. Dorin Goian struck the only goal of the first leg in Poland, and Bănel Nicoliţă and Dorel Zaharia earned them a 2-1 comeback victory in the return.
• Since their sole previous UEFA Champions League group stage appearance in 1995/96, Legia have twice come close to a return only to lose in the final round of qualifying to FC Barcelona in 2002/03 and FC Shakhtar Donetsk in 2006/07.
FC Schalke 04 v PAOK FC
• PAOK's new coach, Huub Stevens, will need no introduction given his two spells managing Schalke, the first of which yielded the 1997 UEFA Cup as well as German Cup triumphs in 2001 and 2002. Stevens' second stint ended only last December.
• It was against Greek opposition that Schalke, with Stevens at the helm, posted that solitary home victory in Europe last season, Christian Fuchs' goal securing a 1-0 success against Olympiacos FC.
Fenerbahçe SK v Arsenal FC
• Arsenal were 5-2 winners when they last visited the Sükrü Saraçoglu Stadium in the 2008/09 UEFA Champions League group stage – a result that ended Fenerbahçe's 15-match unbeaten home run in Europe.
• Fenerbahçe's Emre Belözoğlu (Newcastle United FC 2005–08), Dirk Kuyt (Liverpool FC 2006–12), Raul Meireles (Liverpool FC 2010–11 and Chelsea FC 2011–12) and Joseph Yobo (Everton FC 2002–10) have all had spells in English football.