Europa League semi-finals: Arsenal vs Valencia and Chelsea vs Frankfurt dates and times | The Independent

Alexandre Lacazette scored the only goal of the game as Arsenal booked their place in the Europa League semi-finals with a clinical 1-0 win at Napoli.Leading 2-0 from the first leg, Unai Emery's side reserved arguably their best performance of the season for their potentially daunting trip to the San Paolo.Lacazette fired home a 25-yard free-kick in the 36th minute and, although Arkadiusz Milik had earlier had a goal ruled out for offside, the Gunners seldom looked troubled.From 15p €0.18 $0.18 USD 0.27 a day, more exclusives, analysis and extras.They will face Valencia , one of Emery's former sides, in the last four after they wrapped up victory in their all-Spanish clash with Villarreal.Leading 3-1 from the away leg, Valencia like the Gunners were always in command as goals from Toni Lato and Daniel Parejo gave them a 5-1 aggregate victory. Chelsea held off a second half fightback from Slavia Prague to beat the Czech side 4-3 at Stamford Bridge and move into the last four with a 5-3 aggregate win.