Manchester United failed to usurp Real Sociedad at the top of Europa League Group E despite a 1-0 win in San Sebastian, while Arsenal secured their place in the round of 16 on Thursday.
United now face a tough playoff against one of the teams that fell in the Europa League from the Champions League in February with Barcelona and Juventus as potential opponents.
Alejandro Garnacho scored the night’s only goal at the Royal Arena after just 17 minutes, overtaking George Best as United’s youngest non-English goalscorer in Europe at 18.
But the Red Devils were left to regret the defeat to the Spaniards at Old Trafford on Matchday 1 as they lost the lead by goal difference.
“You don’t always get what you deserve, this is football,” said United manager Erik Ten Hag.
“Today we win, but obviously we are disappointed not to have scored two goals because that was what we needed.”
Arsenal did not make the same mistake: a 1-0 win over FC Zurich was enough to keep PSV Eindhoven at bay and win Group A.
But Mikel Arteta’s men were forced to work for three points after Kieran Tierney’s opening goal put them ahead.
Arteta was forced to sit on the bench in the second half with Bukayo Saka and Thomas Partey took risks despite Sunday’s trip to Chelsea for the Premier League leaders.
And the Gunners had a close escape when Adrian Guerrero shot home for the Swiss champions only to be stopped offside.
Roma won the showdown with Ludogorets Razgrad to go to the playoff round thanks to a comeback in the second half in the Italian capital.
The winners of the first edition of the Europa Conference League were returning to that competition when the Bulgarians led 1-0 at half-time.
But two penalties from Lorenzo Pellegrini and a late goal from Nicolò Zaniolo gave Jose Mourinho’s men the lead.
Feyenoord and Midtjylland moved from an incredibly tight Group F that saw all four teams finish with eight points.
The Dutch giants beat Lazio 1-0 in Rotterdam thanks to a goal from Santiago Gimenez.
Midtjylland beat Sturm Graz 2-0 thanks to a brace from Anders Dreyer.
Union Berlin, Nantes and Monaco also won to secure a move to the playoffs.
Arsenal and Sociedad will be joined by Fenerbahce, Real Betis, Union Saint-Gilloise, Feyenoord, Freiburg and Ferencvaros to go directly to the round of 16.
In the Europa Conference League Anderlecht, Lech Poznan, Nice, Partizan Belgrade, Gent and Cluj secured their place in the knockout stage.
West Ham completed a perfect six out of six group stage despite fielding a young side in a 3-0 win at FCSB in Bucharest.