Chris Boyd admitted it was 'a classic game of two halves' after Saints secured a crucial 31-17 bonus-point win against Newcastle Falcons at Kingston Park on Friday night.
A first-half hat-trick from Tom Collins allied with a late score from super-sub Alex Mitchell earned a maximum haul for the black, green and gold.
It means they move up to fourth in the Gallagher Premiership standings, while Newcastle remain seven points adrift at the bottom of the table and the Falcons could be relegated if Worcester beat Gloucester at Sixways on Sunday.
Saints had led 24-3 against Newcastle thanks to a blistering first-half display.
But the Falcons fought back well after the break, before Mitchell's intercept score settled it.
And Boyd said: "It was a classic game of two halves.
"It's a really interesting question why we stopped playing in the second half, but credit to Newcastle.
"I thought we were pretty decent for 30 minutes in the first half and we got a pretty good lead at half-time.
"We were talking at half-time about not shutting up shop and wanting to score next.
"We knew that they would have to come with a different plan in the second half, which they did.
"They closed us down off the edges and we couldn't get the ball into that space anymore.
"We got taken on physically and we started dropping off tackles and we couldn't get the ball.
"It was a side that was desperately keen to stay in the race to stay in the Premiership and they put the blow torch on us for 30 minutes, which we didn't handle particularly well, which was disappointing.
"But in the end a little sneaky tearaway from Alex Mitchell two games in a row (Mitchell also scored late on at Harlequins) got us five points on the road, which is great.
"Both Alex and Cobus practice that (intercept try off the back of a lineout), they're quick and he was well onside.
"We feel for Newcastle but we're happy to come here and get five points."