Arsenal produced one of the memorable performances in Barclays Premier League history to stun Chelsea 5-3 at Stamford Bridge.
Robin Van Persie was the hero for the visitors, scoring a hat-trick for Arsene Wenger's side in a game that twisted towards both sides throughout.
Frank Lampard gave the Blues the lead, and John Terry restored the advantage on the stroke of half-time after Van Persie has leveled.
Andre Santos grabbed another equaliser at the start of the second period and Theo Walcott put the visitors in-front, only for Juan Mata to score from distance to leave the match in the balance.
But a slip from Terry allowed the Dutch hitman to round Petr Cech late-on, and he scored his third in injury-time to seal a memorable victory.
Andre Villas-Boas' side made a bright start, and Lampard broke the deadlock with a close-range header on 14 minutes.
Van Persie made it 1-1 on 36 minutes, slotting into an empty net after Gervinho cleverly passed across goal when one-on-one with Cech. However, Terry's header from a corner in first-half injury time put the hosts in-front again.
Brazilian full-back Santos found plenty of space to fire past Cech at the near post on 49 minutes, and six minutes later Walcott picked himself up off the floor, skipped past two defenders and fired home.
Mata's long-range effort on 80 minutes set up a grandstand finish, but it was Arsenal who nudged ahead again when Florent Malouda's loose pass backwards evaded Terry. Van Persie rounded Cech, and tapped in with his right foot.
As Chelsea pushed for an equaliser, Arsenal hit on the counter attack, and Van Persie rounded off the scoring with a swerving shot that evaded the keeper from 18 yards to end an extraordinary clash in west London.