EPL power: Arsenal, Chelsea seal incredible feat
For the first time in 35 years, four English teams will appear in the semi-finals of major European competitions for the same season.
Chelsea and Arsenal are into the final four of the Europa League after turning in strong performances in their second leg clashes against Slavia Prague and Napoli respectively on Friday (AEST).
The Gunners won 1-0 in Naples to complete a 3-0 aggregate victory care of Alexandre Lacazette's stunning free-kick.
Meanwhile, Chelsea got home 4-3 in a thriller at Stamford Bridge, meaning a 5-3 aggregate triumph after a goalfest.
They'll be joined by Valencia and Eintracht Frankfurt in the semi-finals.
NAPOLI 0-1 ARSENAL (0-3 ON AGG)
Alexandre Lacazette's free-kick calmed any nerves as a defensively stoic Arsenal beat Napoli 3-0 on aggregate to reach the Europa League semi-finals.
Lacazette's strike, a 25-yard curling effort which caught Alex Meret on the wrong side of his goal, put Arsenal effectively four goals up on their hosts, who did not trouble Petr Cech enough to even hint at mounting an unlikely comeback in Thursday's quarter-final second-leg tie.
On a night when Napoli had let fans into their San Paolo stadium nearly three hours before kick-off, instead of inspiring their team, the partisan atmosphere seemed to intimidate the hosts, who managed only one shot on target before half-time when Jose Callejon was denied by Cech's legs following a rapid counter.
After half-time, Meret kept Napoli's faint hopes alive by denying Pierre-Emerick Aubameyang a seemingly open goal with a stunning save, while Arkadiusz Milik wasted a fine chance, sliding too early to meet Mario Rui's cross and firing wide when the ball rebounded off his midriff on one of the few occasions Napoli breached an impressive Arsenal backline.
Arsenal progress to face Valencia, one of manager Unai Emery's former sides, in the semi-finals, with the prospect of a first European final in 13 years well within sight.
CHELSEA 4-3 SLAVIA PRAGUE (5-3 ON AGG)
Pedro scored twice for Chelsea as they beat Slavia Prague 4-3 (5-3 aggregate) in a thrilling game to progress to the Europa League semi-finals.
Pedro gave Chelsea an early lead (5) before Simon Deli's unfortunate own goal extended Chelsea's advantage (10).
Olivier Giroud scored Chelsea's third on the night - and his tenth in the competition this season - with a simple tap-in (17) before Pedro added Chelsea's fourth (27) - 63 seconds after Slavia captain Tomas Soucek pulled a goal back (26).
But Slavia did respond in the second half as two quickfire goals from Petr Sevcik (52 and 54) gave the Czech visitors hope of a comeback. But in the end Chelsea progress through to the semi-finals and will play Frankfurt.
EINTRACHT FRANKFURT 2-0 BENFICA (4-4 ON AGG)
Eintracht Frankfurt have marched on after getting past Benfica on away goals.
Strikes from Filip Kostic and Sebastian Rode got the job done in the second leg, but it wasn't without controversy with the former appearing to come from an offside position to net the opener.
The German side are into the final four!
VALENCIA 2-0 VILLARREAL (5-1 ON AGG)
Valencia's incredible run of form has continued, romping past their La Liga rivals to nab a place in the semi-finals.
Goals from Toni Lato and Dani Parejo were enough to seal victory in their home leg.