A second-half goal by Robin van Persie gave Arsenal a 1-0 victory over Steaua Bucharest on Tuesday.
Pep Guardiola's ManchesterCity will play Romanian side Steaua Bucharest in the Champions League playoff round after the draw was made in Nyon on Friday.
AS Roma secured their place in the Europa League last 16 with a 3-2 home win over 10-man Porto on Thursday thanks to a Paulo Dybala double, advancing 4-3 on aggregate.
A round-up of Thursday's Europa League Round of 16 second leg matches.
Francisco Moura's second-half strike earned hosts Porto a 1-1 draw against 10-man AS Roma in the first leg of their Europa League knockout round play-off on Thursday.
Manchester United were handed a tricky Europa League last 16 tie against Real Sociedad while Tottenham Hotspur will play Dutch side AZ Alkmaar after the draw was held on Friday, but both managers are more concerned about their Premier League form.
Forward Rasmus Hojlund scored twice to allow Manchester United to come back from a goal down and get a 2-1 win at six-times Czech champions Viktoria Plzen in the Europa League on Thursday.
IMAGES from Europa League matches played on Thursday.
IMAGES from the Premier League matches played on Sunday.
Chelsea led a trio of English clubs into the Europa League quarter-finals on Thursday after Tottenham Hotspur survived a thrilling Inter Milan fightback to advance on away goals and Newcastle United got a late winner.
Schalke 04 scored twice after being reduced to 10 men to win 3-2 at PAOK and reach the Champions League group stage on Tuesday and there were dramatic playoff victories for Austria Vienna and Steaua Bucharest.
Five-times European champions Liverpool survived a late scare to move into the last 32 of the Europa League with a 1-0 win over Italian side Udinese on Thursday.
Tottenham Hotspur trounced a sorry Inter Milan 3-0 in the Europa League on Thursday while last year's European champions Chelsea were humbled 1-0 by Steaua Bucharest after being stung by a Raul Rusescu penalty.
Striker Luis Suarez scored one goal and missed two second-half penalties as Ajax Amsterdam beat nine-man FC Timisoara 2-1 in Romania on Wednesday to reach the knockout stage of the Europa League.
Napoli recovered from three goals down to draw 3-3 at Steaua Bucharest in the Europa League on Thursday as holders Atletico Madrid were held 1-1 by Bayer Leverkusen.
The Champions League burst into life on Tuesday with 36 goals in eight matches, including 24 in just three games, to equal a competition record.
Middlesbrough scored four times in an hour to beat Steaua Bucharest 4-2 to reach the UEFA Cup final for the first time
Manchester United suffered a setback as they were shocked by FC Copenhagen.
Manchester United routed Dynamo Kiev 4-0 while a goalless draw saw Arsenal through to the Champions League knockout stages.
Sevilla maintained their brilliant record at home in Europe with a 2-1 win over Steaua Bucharest in the Champions League.
Claudio Ranieri was sacked as Valencia coach on Friday just eight months after taking charge at the Primera Liga club.
Middlesbrough beat Basel 4-1, putting them through 4-3 on aggregate and into a meeting with Steaua Bucharest.
The Liverpool striker has been suffering from various leg injuries.
West Bromwich Albion inflicted further misery on Manchester United, winning 2-1 at Old Trafford on Saturday to condemn the champions to their worst start to a Premier League season and leave them in the bottom half of the table after six games.
Chelsea striker Fernando Torres will be out for three weeks after suffering a knee injury in the 4-0 Champions League Group E victory over Steaua Bucharest in Romania, the club said on Wednesday.
Midfielder Yaya Toure has apologised to Manchester City for the "misunderstandings" that have resulted in him being frozen out of manager Pep Guardiola's team. Guardiola has refused to pick the 33-year-old until he receives an apology from the player's agent, Dimitri Seluk, who criticised the manager's decision to leave Toure out of City's Champions League squad.
Former European champions Steaua Bucharest and English Premier League Southampton suffered shock defeats by Scandinavian teams in Europa League qualifiers on Thursday.
Yaya Toure's agent says the Manchester City midfielder plans to stay and fight for his place despite being left out of their first game of the season. The Ivorian, who played under new manager Pep Guardiola when the pair were at Barcelona, was omitted for Saturday's narrow 2-1 win over Sunderland in City's Premier League opener.
Manchester City striker Sergio Aguero has been banned for three matches after being found guilty of violent conduct, the Football Association said on Friday.
A former Playboy model has completed a takeover of debt-ridden top division club AFC Hermannstadt.