As one Beckham tried in vain to conceal his identity, the other was unmistakable, charging down the wing, clad in bright red boots and serving up a fine line in the family trademark: whipped crosses from the right.
Romeo, the second-eldest son of Posh and Becks, has been training with the Bees for the past few months but last week formally signed on loan from Inter Miami II, the reserve side of the MLS franchise co-owned by his father.
The 20-year-old was introduced as a second-half substitute around the hour-mark, with Brentford trailing ninth-tier Erith and Belvedere 2-1 in the London Senior Cup, but played his part in a late comeback that carried Neil MacFarlane's side into the third round with a 3-2 win.
Wearing the No21 jersey, it was Beckham's corner that led to a late equaliser for Kyreece Lisbie — another famous footballing son, that of former Charlton man Kevin — before Michael Olakigbe struck a deflected 93rd-minute winner to keep the holders' defence of their trophy alive.
Beckham Sr was smuggled into the ground incognito, wearing a black hat and coat with hood up, but was soon spotted by local fans and mobbed, as those in attendance sought photos and autographs.
There were plenty of them, too. A crowd of 553 was more than three times Erith and Belvedere's average attendance and a new record for one of their matches played on this ground, which is shared with National League South side Welling United.
For those watching at home, there was disappointment, though, as technical issues derailed Brentford's online stream before half-time.
"[Romeo's] father was an unbelievable player, with an unbelievable character, who had an unbelievable career," said MacFarlane at full-time.
"We push the players like they have never been pushed before and [Romeo] has been incredible and bought into the culture and he should be proud of his debut."