The former footballer starred opposite Sir David Jason (Del Boy) and Nicholas Lyndhurst (Rodney) in the one-off skit for Sport Relief.
The Only Fools short saw Del Boy and Rodney trying to flog 'Golden Balls' boxers, which Rodney begrudgingly modelled.
Sitting in the cafe, Del Boy was moaning about 'that git' who signed the pants, only for Beckham himself to correct him: "They're boxer briefs."
Beckham, as well as delivering the classic line "Shut up you tart" to Rodney, also told Del Boy's younger brother exactly how to model the boxers.
Swapping their favourite artist picks, Rodney went for Matisse while Beckham chose Tony Hart: "That Morph cracks me up."
Trying to keep a low-profile in the market, Beckham then drew attention to himself in a humiliating incident which paid tribute to the late actor Roger Lloyd-Pack (Trigger).
The ex-Manchester United player recently said that he found filming the special sketch "nerve-wracking".
Jason has also admitted that he never expected to return to Only Fools and Horses.
Jim Sullivan - the son of late creator John Sullivan - has confirmed that there are no plans for it to return for further episodes.
To make a donation to Sport Relief, call 03457 910 910 now or go to the Sport Relief website.