After departing West Ham United to join Chelsea in 2001, Frank Lampard quickly became a hated figure at Upton Park, but he always seemed to get the better of his old side during his time with the Blues.
Lampard is still producing the goods in the Premier League with Manchester City, but it was during Jose Mourinho's first reign when the England international was in his prime as one of Europe's most feared midfielders.
On this day in 2006, Lampard returned to Upton Park once again to pile misery on the Hammers with a goal and a fine display in a 3-1 victory for Chelsea as their successful defence of the title continued.
The jeers directed at the West Ham academy graduate started inside the first minute, but he came close to silencing the crowd immediately when a dipping strike forced Roy Carroll into a good save.
Carroll was called upon to make another early stop from Arjen Robben's volley as the lively Asier del Horno threatened the hosts with his crossing from the left.
Chelsea were finally rewarded for their dominance in the 25th minute, but it was a goal that should have been avoided as Yossi Benayoun's weak header fell kindly for Lampard, who fired home his 13th goal of the campaign to the delight of the visiting supporters.
After being forced onto the back foot for the majority of the first half, it came as a big surprise to see West Ham equalise in the first minute of the second half.
A clever pass from Nigel Reo-Coker caught the Chelsea defence napping, and Marlon Harewood took advantage by slotting home after Petr Cech had saved his initial effort.
It was then time for Mourinho to stamp his authority on the game by taking the surprise move of switching to two strikers, with Hernan Crespo coming off the bench to join Didier Drogba in attack.
The change worked almost immediately as the Argentine forward collected a through-ball before rounding Carroll to tap home 45 seconds after replacing Damien Duff.
Crespo's movement was causing problems for the Hammers every time Chelsea came forward, but he missed two good chances to get his second of the game.
However, the missed opportunities would not prove to be costly as Chelsea secured the win late on when Drogba picked out the bottom corner following good work from Eidur Gudjohnsen.
"We made the change, introducing Hernan Crespo, and it worked immediately," Mourinho told reporters after the game. "After that we had many chances to score four of five but West Ham did not deserve that. It was a good game."
For Lampard, scoring against his former side will always be a special achievement, but in truth, this was just one more win in a dominant campaign for Chelsea as they finished eight points clear of Manchester United.
West Ham: Carroll, Dailly, Ferdinand, Collins, Konchesky, Benayoun, Fletcher, Reo-Coker, Mullins (Zamora), Etherington (Bellion), Harewood
Chelsea: Cech, Geremi, Ricardo Carvalho, Terry, Del Horno, Duff (Crespo), Essien (Gudjohnsen), Lampard, Makelele, Robben, Drogba, Crespo (Wright-Phillips)