While Chelsea versus Arsenal matches are often difficult to call, their meeting at Stamford Bridge two years ago today appeared, on paper at least, to be a straightforward one to predict.
The hosting Blues had a 100% winning record at Stamford Bridge, while Arsenal had failed to emerge victorious away from home in the Premier League so far that season.
What's more, when Frank Lampard headed in a cross by Juan Mata to break the deadlock in West London with 14 minutes on the clock, the home side looked to be a sure bet.
However, there was not a more in-form striker in European football at that time than Robin van Persie, and Arsenal's frontman drew the Gunners level with 36 minutes played when he turned in Gervinho's square pass.
Chelsea went back in front before the half-time whistle, though, courtesy of skipper John Terry, who had been accused of racially abusing Queens Park Rangers defender Anton Ferdinand during a fixture at Loftus Road a week earlier.
Nevertheless, Arsene Wenger's visitors refused to concede defeat and within four minutes of the restart they equalised for a second time when Brazilian full-back Andre Santos slotted beyond the reach of Petr Cech.
They then took the lead in the 55th minute when Theo Walcott used his pace and balance to ride two Chelsea challenges, before going on to fire the ball into the net.
Back came Chelsea, who with 10 minutes left to play looked to have secured a share of the spoils when Spanish international Mata sent a swerving effort in from 25 yards out.
Van Persie would steal the headlines, though, as he completed his hat-trick to seal the victory for Arsenal. First he capitalised on a slip from Terry to send his team 4-3 up and then put the outcome beyond any doubt in stoppage time, taking his tally to 28 goals in 27 Premier League matches.
"Robin is on fire at the moment. His class means he is taking advantage of being in a team that wants to attack a lot and create chances. The intelligence of his movement and the accuracy of his finishing is exceptional," Wenger said during his post-match press conference.
CHELSEA: Cech; Bosingwa, Ivanovic, Terry, Cole; Ramires (Lukaku), Lampard, Mikel (Meireles), Mata; Torres, Sturridge (Malouda)
ARSENAL: Szczesny; Santos, Mertesacker, Koscielny, Djourou (Jenkinson); Arteta, Ramsey, Song; Walcott (Rosicky), Gervinho (Vermaelen); Van Persie