Jim Mallinder says Saints must step it up if they are to see off Stade Français at Franklin's Gardens on Friday night.
Mallinder's men defeated Connacht on Saturday, scrapping their way to a 21-15 victory at the Gardens.
Harry Mallinder grabbed a try and kicked 11 points, with scrum-half Nic Groom adding the other Saints score.
And now Saints will be desperate to secure one more win, which would earn them a place in next season's Champions Cup.
But the task will not be an easy one against a rampant Stade side, who can call on the likes of Sergio Parisse, Will Genia and Jules Plisson.
The French giants recently beat Gloucester in the Challenge Cup final and set up a showdown with Saints by smashing Cardiff Blues 46-21 in Paris last Friday.
And Mallinder knows just how tough the test will be for his team, who finished seventh in the Aviva Premiership.
"We know that Friday is the end of the season for the team and we've got Stade coming to town with an array of internationals," the Saints boss said.
"I saw their game against Cardiff. They're playing well and I think it will be a cracking match.
"We are going to have to step up, but there's no reason why we can't do that.
"We have stepped up against the big sides this season - we've got a good side."