Arsenal and Chelsea are still on course for a potential all-English Europa League Final after reaching the last four of the competition.
Chelsea saw off Slavia Prague at Stamford Bridge on Thursday night to progress, while Arsenal held off Napoli in Naples as Unai Emery further enhanced his reputation as a Europa League specialist.
Arsenal headed to Naples defending a 2-0 first-leg lead, and Alexandre Lacazette's fine free-kick was enough to see off a limp Napoli performance as the Gunners went through 3-0 on aggregate.
As for Chelsea, they were made to work harder for their win. The Blues has won the first leg 1-0 in Prague, but Slavia threatened an astonishing Stamford Bridge comeback - only to lose 4-3 on the night, and 5-3 on aggregate.
Arsenal's reward for reaching the last four is a semi-final against Valencia - who knocked out fellow LaLiga club Villarreal - while Maurizio Sarri's Chelsea will take on Eintracht Frankfurt after the Bundesliga club completed a comeback against the Portuguese giants.
