A quick-fire first-half hat-trick from striker and captain Roberto Soldado, and goals from Jonas, Pablo Hernandez, Aritz Aduriz and Tino Costa, gave Emery's side a crushing 7-0 win over the Belgians at the Mestalla.
That result is one goal short of Liverpool's record 8-0 destruction of Besiktas in 2007.
A score draw at Stamford Bridge on December 6 would be enough to secure a berth in the last 16 after Chelsea were upset 2-1 in Germany by Bayer Leverkusen, who went top of Group E and sealed their place in the knockout round.
"We have a chance in London to see what we are capable of in this competition and against a powerful opponent," Emery, whose side drew 1-1 with Chelsea in Valencia in September, said at a post-match news conference.
"We'll have to prepare with a lot of strength and intelligence, but we should try to enjoy it as well. We have our fate in our own hands and for that we should be satisfied.
"We'll go to London to win."
Valencia's solid start to the season has been built around the splendid form of Soldado, the former Real Madrid, Osasuna and Getafe forward, who has netted five in Europe's elite club competition and eight in La Liga, where Valencia are third behind leaders Real and second-placed Barcelona.
Soldado's latest performance, coming after his double against Real in La Liga at the weekend, will boost his chances of a recall to the Spain squad for next year's European Championship in Ukraine and Poland.
The 26-year-old, who was born in Valencia, has represented the world and European champions only twice, back in June 2007, when he failed to score.
"He is improving every day and he will get a chance to play for the national team if he carries on like this," Emery said.
