Saints will host Harlequins in the semi-finals of the Amlin Challenge Cup.
The tie will take place at Franklin’s Gardens on Friday, April 25, with an 8pm kick-off.
Harlequins booked their place in the final four with a comfortable 29-6 victory against Stade Francais in Paris on Friday night.
Saints progressed 24 hours earlier thanks to a similarly convincing success, disposing of Sale Sharks 28-14 at the AJ Bell Stadium.
Ben Nutley grabbed a brace, with Sam Dickinson and Ben Foden also dotting down to take Jim Mallinder’s men to within one win of the Cardiff showpiece.
And Saints should be confident, having won both games against Harlequins this season, earning a 13-6 victory at The Stoop in September and a 23-9 win at the Gardens in January.