Arsenal survived a major scare to reach the Europa League last 16, beating Ostersunds 4-2 on aggregate despite a 2-1 loss on Thursday.
Arsene Wenger's side conceded twice within 70 seconds in the first half at the Emirates Stadium and managed only a solitary Sead Kolasinac strike in return, although their 3-0 first-leg win was enough to see them through.
Borussia Dortmund battled past Atalanta in Bergamo to reach the next round, while Atletico Madrid and AC Milan picked up 1-0 wins to ease through comfortably.
There were tragic scenes in Bilbao, though, where a police officer died following clashes between fans ahead of the meeting between Athletic Bilbao and Spartak Moscow.
Complacent Arsenal survive, Celtic crash out
A Calum Chambers own goal and a fine strike from Ken Sema gave Ostersunds a 2-0 half-time lead over Arsenal, leaving the Gunners fearing a spectacular collapse.
Kolasinac's strike just after the break eased some of the anxiety around the Emirates, but Arsene Wenger will have been concerned by the complacent performance, while Ostersunds celebrated a famous win.
Celtic took a 1-0 lead into their second leg with Zenit but offered meek resistance against the Russians, who ran out 3-0 winners to advance 3-1 on aggregate.
Branislav Ivanovic, Daler Kuzyaev and Aleksandr Kokorin got the goals for Roberto Mancini's side.
6 - Graham Potter is just the sixth English manager to win at the Emirates in all competitions after (Alan Curbishley, Phil Brown, Harry Redknapp, Michael Appleton and Garry Monk), but the first to do so in European competition. Future. pic.twitter.com/mUFkE5RVBG— OptaJoe (@OptaJoe) February 22, 2018
Atletico advance, Bilbao win soured by violence
Atletico made light work of their second leg against FC Copenhagen, with Kevin Gameiro's fine strike securing a 1-0 win on the night and a 5-1 triumph on aggregate.
Bilbao lost 2-1 to Spartak Moscow but still advanced 4-3, although their success was marred by violent clashes between fans before kick-off, which saw a police officer involved in attempts to restore order die after suffering a heart attack.
Basque rivals Real Sociedad crashed out with a 4-3 aggregate loss to Red Bull Salzburg, who won 2-1 in Austria thanks to Valon Berisha's second-half penalty.
Meanwhile, a number of Marseille fans missed kick-off due to problems at Braga's stadium, but the Ligue 1 side's 1-0 defeat did not stop them going through 3-1 on aggregate.
Dortmund battle through, AC Milan make it look easy
Dortmund were staring at an away-goals defeat to Atalanta until Marcel Schmelzer struck seven minutes from time in Bergamo, thereby securing a 1-1 draw and 4-3 aggregate triumph.
There was an unsavoury incident involving Michy Batshuayi, though, who took to social media to accuse some home fans of racist abuse after the match.
Milan made light work of Ludogorets, with Fabio Borini's effort sealing a 1-0 second-leg win and 4-0 aggregate success, ensuring a second Serie A presence in the last 16.
|Cardinals´ Fitzgerald makes NFL history with most receptions for one team|
|River Plate´s Copa Libertadores star Gonzalo Martinez confirms January departure|
|Klopp: I was never worried about Salah´s form|
|Packers QB Rodgers sets NFL record for most passes without an interception|
|World Cup bulking hampered Man United form – Lukaku|
|Leonardo rules out Ibrahimovic Milan return|
|Warriors´ Green to return against Timberwolves|
|I feel for him… we´ll make it work – Butler responds to Embiid´s frustration|
|Torino draw no missed opportunity for misfiring AC Milan, claims Gattuso|
|We´ll always be linked together forever - Wade reflects on playing with James before final match-up|
|O´Sullivan wins record seventh UK title|
|Chiefs secure playoff berth, Saints win NFC South|
|River Plate 3 Boca Juniors 1 (aet, 5-3 agg): Quintero and Martinez clinch Libertadores title in extr|
|WATCH: Chiefs QB Mahomes throws no-look pass|
|Dolphins defeat Patriots on miraculous final play|
|Kizzire eagle snatches QBE Shootout victory|
|AC Milan 0 Torino 0: Donnarumma shines, Cutrone misses late chance|
|Back to the drawing board for West Indies - Chase|
|Copa Libertadores: Messi and Griezmann among stars in Madrid for River-Boca Superclasico|
|Brady sets NFL record for most career TD passes|
|Copa Libertadores: Tevez named on Boca bench for Superclasico final|
|Premier League needs VAR, right now! - Benitez fumes over Dean´s decisions|
|McCall expects Itoje to fit for the Six Nations|
|Solari salutes Real Madrid character after ´ugly´ Huesca win|
|Berbatov defends under-fire Lukaku|
|Sarries crush Blues to maintain unbeaten start|
|Newcastle United 1 Wolves 2: Doherty punishes Yedlin red with late winner|
|Deeney jokes he´ll ´smash´ former Watford star Richarlison|
|Huesca 0 Real Madrid 1: Bale ends drought as Solari´s men edge to victory|
|Ponting: Umpires not looking at no-balls|
|Bale ends longest LaLiga goal drought|
|Porter backs Brees for MVP, Saints for Super Bowl|
|Verstappen eyeing 2019 title fight|
|Wall ´shouldn´t have played´ against Cavaliers after scoring just one point|
|Hazard: Man City the best team in the Premier League despite Chelsea win|
|LeBron explains why he gave a Grizzlies employee his game-worn shoes|
|Bangladesh cruise to ODI victory as seamers punish Windies|
|Football will win over violence, claims CONMEBOL president|
|Alcorcon support Reus Deportiu over unpaid players|
|Saponara explains cheeky celebration after last-gasp leveller|
|Godin and Filipe Luis return to Atletico training|
|Kick It Out condemns alleged racist abuse of Sterling|
|Emotional Oosthuizen clinches South African Open title|
|The Sunday Seven - 7 Key Opta facts for NFL Week 14|
|Martino salutes Atlanta´s grand plan|
|India´s tail must show greater application - Bangar|
|Mourinho: Diogo Dalot can be new Gary Neville|
|Sterling hits out at media coverage of black players|
|Lyon roars with defiance as Australia aim for unlikely victory|
|Bulls coach Boylen: Hooked starters ´embarrassing´ in record loss|
|Martinez pays tribute to Martino, Almiron after MLS Cup glory|
|LeBron: Final Wade matchup will be bittersweet|
|Alvarez-Kovalev rematch set for February 2|
|Newcastle Jets 2 Brisbane Roar 0: Sheppard, Jair score first A-League goals|
|India close in on victory in first Test|
|LeBron flirts with triple-double as Lakers down Grizzlies|
|Lomachenko unifies WBO, WBA titles with win over Pedraza|
|Joshua wants Wilder and Fury fights – Hearn|
|Mavericks rookie Doncic leads impressive fourth-quarter surge to beat Rockets|
|Martinez named MLS Cup MVP|
|Oklahoma´s Murray wins the Heisman Trophy|
|Atlanta United 2 Portland Timbers 0: Martinez scores again as Martino´s men win MLS Cup|
|Sarri to use Hazard as centre forward again|
|Ballon d´Or is a lie – Alba says Messi is world´s best|
|Messi: I needed some luck with free-kicks|
|Hoffman, Woodland in three-way tie for lead|
|Brook unconvincing in Zerafa victory|
|Leo unties any game - Valverde hails mesmeric Messi|
|Pochettino: Walker-Peters ready for Barcelona challenge|
|Messi showed he is world´s best - Busquets|