Alexandre Lacazette's late goal in Greece has given Arsenal the advantage, although Olympiacos won their last game away to the Gunners.
Arsenal struck late to defeat Olympiacos 1-0 in Piraeus, and the 2018/19 runners-up have history on their side as they seek to close out this UEFA Europa League round of 32 tie, even though the Greek side were victorious on their last visit to the Gunners' home.
• Arsenal's third successive UEFA Europa League group stage campaign began with three straight wins, but they stuttered thereafter and needed a late comeback at Standard Liège on Matchday 6 to qualify as Group F winners. Olympiacos competed in the UEFA Champions League during the summer and autumn, coming through three qualifying ties before claiming third place in Group B behind Bayern München and Tottenham Hotspur thanks to a closing 1-0 win at home to Crvena zvezda.
• Alexandre Lacazette's close-range strike in the 81st minute – the Frenchman's 19th UEFA Europa League goal – proved to be the difference between the two sides in the first leg as Arsenal claimed a second successive victory over Olympiacos in Piraeus.
• The clubs have been paired together four times in the UEFA Champions League group stage, and on every occasion Arsenal have staged the home fixture on Matchday 2 and Olympiacos the return game on Matchday 6.
• The first six matches between them – in 2009/10, 2011/12 and 2012/13 – all ended in home wins, but last time out, in 2015/16, the roles were reversed, Olympiacos winning 3-2 in north London only to succumb to a 0-3 defeat at home. Olivier Giroud's hat-trick enabled Arsenal to pip their hosts to the runners-up spot in the group on the head-to-head rule and therefore secure a 16th successive appearances in the UEFA Champions League knockout phase.
• Arsenal's record at home to Greek visitors is W6 D2 L1, Olympiacos's most recent visit ending their unbeaten run. The Gunners have kept only two clean sheets in those nine fixtures.
• The 3-2 win at Arsenal in September 2015 ended Olympiacos's sequence of 12 defeats in as many visits to England. Since then they have drawn 1-1 at Burnley in last season's UEFA Europa League play-offs and lost 4-2 at Tottenham in this season's UEFA Champions League group stage.
• UEFA Champions League ever-presents for 19 successive seasons from 1998/99 to 2016/17, Arsenal reached the UEFA Europa League semi-finals at the first attempt in 2017/18, losing to eventual winners Atlético Madrid, before going one step further and making it to last season's final, where they were defeated 4-1 by London rivals Chelsea.
• Fifth place in the 2018/19 Premier League secured a third successive UEFA Europa League group stage berth for the Gunners, and they appeared to be cruising to the round of 32 when they opened with big wins against Eintracht Frankfurt (3-0 a) and Standard (4-0 h). Forced to come from behind to beat Vitória SC 3-2 at home on Matchday 3, they then drew 1-1 in Portugal and lost 1-2 at home to Eintracht before squeezing through in first place thanks to two late goals in Liege after they had gone 2-0 down.
• Arsenal have won both of their previous UEFA Europa League round of 32 ties, but in different circumstances. In 2017/18 they won the first leg 3-0 in Sweden against Östersund before losing 1-2 at home; a year later they were defeated 1-0 at BATE Borisov but recovered to win the home leg 3-0.
• The Gunners' seven-match winning streak at home in this competition ended with that defeat by Eintracht on Matchday 5. Their overall UEFA Europa League record in the Arsenal Stadium is W12 D3 L2.
• Arsenal have won 15 away first legs in UEFA competition and qualified on each occasion, most recently in the 2017/18 UEFA Europa League round of 16 when they knocked out AC Milan after a 2-0 win in Italy (3-1 h). Only once previously have they triumphed 1-0 on the road in the first leg, against Real Madrid in the 2005/06 UEFA Champions League round of 16 (0-0 h).
• Second in the 2018/19 Greek Super League behind PAOK, Olympiacos went from the UEFA Europa League third qualifying round to the round of 32, where, having memorably eliminated Milan in the group stage, they were knocked out by Dynamo Kyiv (2-2 h, 0-1 a).
• This season Olympiacos returned to the UEFA Champions League group stage, earning their 19th participation with convincing qualifying victories over Viktoria Plzeň, İstanbul Başakşehir and Krasnodar. However, after drawing their opening group game against Tottenham (2-2), they lost the next four and were indebted to Youssef El Arabi's 87th-minute penalty in their final fixture at home to Crvena zvezda for the win they needed to leapfrog the Serbian champions into third place.
• This is Olympiacos's seventh appearance in the UEFA Europa League round of 32 – and fifth after finishing third in their UEFA Champions League group. They have won just two of the previous six ties at this juncture – against Rubin Kazan in 2011/12 and Osmanlıspor in 2016/17 – and have yet to progress beyond the round of 16. In each of their victorious round of 32 ties they won the away leg; in all four they lost they were beaten in their opponents' stadium.
• Excluding the qualifying phase Olympiacos have lost nine of their last ten European away fixtures, the exception a 2-0 win at Dudelange in last season's UEFA Europa League group stage. In this season's UEFA Champions League they were beaten at Crvena zvezda (1-3), Bayern München (0-2) and Tottenham.
• Olympiacos have won only one of the ten previous UEFA ties in which they lost the first leg at home, a 0-1 defeat preceding a 3-0 away win against Chornomorets Odesa in the first round of the 1992/93 European Cup Winners' Cup. The last time they lost the first leg at home was 0-1 against Bordeaux in the 2009/10 UEFA Champions League round of 16, the French side going on to take the tie with a 2-1 victory in the return.
UEFA Europa League squad changes
In: Cédric (Southampton, loan), Miguel Azeez*, Pablo Marí (Flamengo, loan), Eddie Nketiah*, Tom Smith*
Out: Joel López, Tyreece John-Jules (Lincoln City), Konstantinos Mavropanos (Nürnberg, loan), James Olayinka, Emile Smith Rowe (Huddersfield, loan)
In: Ousseynou Ba, Kostas Fortounis, Christos Liatsos*, Hilal Soudani
Out: Yassine Benzia (Dijon), Daniel Podence (Wolves), Miguel Ángel Guerrero (Leganés, loan), Yassine Meriah (Kasımpaşa, loan), Alexandros Voilis
Links and trivia
• Three Olympiacos players have had brief spells in England – Omar Elabdellaoui (who started his career in Manchester City's youth team) at Hull City in 2016/17, Andreas Bouchalakis at Nottingham Forest in 2017/18 and Hilal Soudani, also at Forest, in 2018/19.
• Arsenal defender Sokratis Papastathopoulos is a long-standing Greek international who started out in his homeland with Olympiacos's local rivals AEK Athens (2005–08).
• Olympiacos midfielder Mathieu Valbuena and Arsenal striker Lacazette are former Lyon (2015–17) and France (2013–15) team-mates.
• Arsenal's victory in the first leg was their 23rd in the UEFA Europa League, group stage to final, setting a new record for an English club, one ahead of arch rivals Tottenham.
• Olympiacos moved five points clear at the top of the Greek Super League on Sunday evening, and maintained their unbeaten record in this season's competition, when they beat title rivals and defending champions PAOK 1-0 in Salonika.
• Arsenal's record in four UEFA penalty shoot-outs is W2 L2:
4-5 v Valencia, 1979/80 European Cup Winners' Cup final
3-2 v Sampdoria, 1994/95 UEFA Cup Winners' Cup semi-final
1-4 v Galatasaray, 1999/2000 UEFA Cup final
7-6 v Roma, 2008/09 UEFA Champions League round of 16
• Olympiacos have yet to feature in a UEFA penalty shoot-out.
• Mikel Arteta left his position as Josep Guardiola's assistant at Manchester City on 20 December 2019 to become Arsenal's head coach, replacing another Spaniard, Unai Emery, and returning to the club where he had spent the final years of his playing career, the last two as captain. A versatile, composed central midfielder, he was born in the Basque country but started his career at Barcelona. It was in England, however, where he blossomed, playing over 200 games for Everton and joining the Gunners in 2011, helping them to two FA Cup triumphs before retiring in 2016 and going straight into coaching as Guardiola's right-hand man.
• Pedro Martins was named Olympiacos coach in April 2018, becoming the club's fifth Portuguese boss in six years after Leonardo Jardim, Vítor Pereira, Marco Silva and Paulo Bento. Martins had not previously worked outside his homeland, his last three spells in the dugout before the move to Greece having brought UEFA Europa League qualification for Marítimo, Rio Ave and Vitória SC. A holding midfielder, he was capped once by Portugal during a three-year spell with Sporting CP from 1995–98.