Last season's runners-up Benfica face Juventus in the Europa League semi-finals, while Sevilla take on Valencia.
Valencia stage a historic fightback to beat Basel 5-3 on aggregate and reach the Europa League semi-finals.
Juventus secure an important Europa League quarter-final first-leg victory as the Italian champions win 1-0 at Lyon.
Napoli FC is fined by European football's governing body after hundreds of Swansea City fans missed the start of their Europa League match in Naples last month.
Benfica face AZ Alkmaar in the Europa League quarter-finals after beating Tottenham, while Juventus meet Lyon.
Rafael Benitez's hopes of a second successive Europa League title were ended as Napoli are knocked out by Porto.
Players in the Salzburg v Basel Europa League match leave the pitch for 12 minutes after missiles are thrown at them.
Tim Sherwood says Tottenham's display in their narrow Europa League defeat by Benfica shows he has his players' support.
Two late Nacer Chadli goals earn Tottenham a draw with Benfica but they still exit the Europa League.
Tottenham boss Tim Sherwood says Benfica coach Jorge Jesus "lacks class" after Spurs' 3-1 Europa League defeat.
Jackson Martinez's second-half goal earns managerless Porto a 1-0 win over Rafael Benitez's Napoli in the last 16 of the Europa League.
Tottenham will need to turn around a two-goal deficit after losing to Benfica in the first leg of the Europa League last-16 tie.
Spurs boss Tim Sherwood says he is not a "babysitter" and will "shoot from the hip" in his assessment of his team's performances.
Uefa begins disciplinary proceedings against SSC Napoli after hundreds of Swansea City fans missed the start of their Europa League match in Naples last month.
Swansea City will make an official complaint to Naples police and Uefa after hundreds of fans missed the start of Thursday's match against Napoli.
Swansea City fans demand answers after hundreds missed the first half hour of their side's Uefa Europa League match against Napoli in Naples.
Wales full-back Ben Davies says Swansea gained 'a lot of respect' following their Europa League exit away at Napoli.
Manager Tim Sherwood wants Tottenham to show their toughness more consistently after a thrilling Europa League win.
Benfica ease past PAOK Salonika, Juventus see off Trabzonspor and Lazio are beaten by Ludogorets Razgrad in the Europa League.
Swansea City manager Garry Monk says he is proud of his players despite their Europa League exit against Napoli.
Features & Analysis
An attempt at transforming South America's second cup competition could benefit the Europa League, says Tim Vickery
BBC Sport looks at how British teams fared in the group stages of the Champions League and the Europa League.
Does German success this season prove the Bundesliga is best? Or will the Spanish sides fight back? Our experts argue it out
Former Liverpool striker Dirk Kuyt on his new career in Turkey with Fenerbahce, and the club and country he left behind