Having not fought since December, Dubois put away Snijders in typically swift fashion, sealing victory inside two rounds to extend his record to 15-0 behind closed doors at the BT Sport studios.
The 22-year-old Londoner has probably had tougher sparring sessions than the challenge put forward by the Dutchman. Dubois swarmed his opponent from the opening bell, flooring Snijders three times in the opening round - the first a shuddering hook to the body delivered right below the ribs.
A fourth knockdown came early in the second round, this time via a right hook, with the referee mercifully stepping in to bring the contest to a close.
Dubois and Joyce have seen their all-London heavyweight showdown postponed twice due to the coronavirus pandemic this year with a new date now beginning to shift into focus on October 24.
Joyce, who had not fought in 12 months, took a tune-up fight in late July, blasting through Michael Wallisch inside three rounds.
And Dubois lived up to his side of the deal, barely breaking a sweat as he swept past Snijders, who was drafted in as a replacement for original opponent Eric Pfiefer 10 days ago.
Focus will now shift to that October date at the O2 Arena for a bout that will see the winner thrust into the world title picture in 2021.
Frank Warren remains hopeful boxing fans will be in attendance on the night. Spectators could return to sporting events across England on October 1 should test events continue to prove successful.
Earlier on the card, Croydon's Sunny Edwards turned in an excellent performance to defend his IBF international super-flyweight title against Thomas Essomba.
Edwards' superb footwork and sharp counter punching saw him ease to a comfortable unanimous points win to move him closer to a world title shot.
Scottish sensation Willy Hutchinson blasted through Ben Thomas inside one round to extend his record to 11-0 with Sam Maxwell securing an unanimous decision win over Joe Hughes in a thrilling super-lightweight contest.
Another London heavyweight David Adeleye also impressed on the bill, extending his professional record to 3-0 after breaking down the durable Phil Williams in the third round.