Alan Dickens has urged Saints to maintain their ruthless streak as they bid to secure a place in the Premiership Rugby Cup final this weekend.
The black, green and gold host Newcastle Falcons in Saturday's semi-final at Franklin's Gardens (kick-off 12.15pm).
And Saints will be out for revenge against a Falcons team they have lost to in each of the past five meetings between the clubs.
Newcastle have claimed late victories on their past two visits to the Gardens, with their most recent success coming via an added time try from Mark Wilson in December.
But Saints have been scoring tries for fun since that stodgy 16-14 defeat, with Chris Boyd's men bagging 30 tries in their past three matches.
And Dickens said: "We need to be clinical on Saturday and in recent weeks we have been pretty good at that.
"We know the strengths Newcastle possess.
"They're a very dogged side, they defend as a group and we saw that when we played them here earlier in the season.
"They're tough to break down and when we get our chances, we've got to be clinical and take them.
"We've also got to be on our mettle when we're defending because they've got a dangerous back three with some good runners in the forwards.
"We've got to manage the game and the game at 50, 60 minutes is going to be tight."
Saints reached the Premiership Rugby Cup semi-finals last season, but they were beaten 13-12 at Bath.
The black, green and gold have not won a first-team trophy since the Premiership title triumph in 2014, and they would love to end that barren run this season.
It was close to a full house at Franklin's Gardens for the Leicester clash last month, and Saints will be hoping for similar support as their bid for silverware continues this Saturday.
"We were in this semi-final last year away in dreadful conditions at Bath and we were pretty unfortunate because we lost by a point," Dickens said.
"We were watching the results on Sunday to see where we'd end up and we're really pleased to have a home semi-final this time.
"The crowd here was fantastic against Leicester two weeks ago and to have around 14,000 people at the Gardens for the Premiership Rugby Cup was great.
"We had some young players experiencing that and it is positive we managed to get the five points we needed to get the home semi-final."