Jim Mallinder admits Saints would have kicked themselves had they not claimed a win at Wasps.
Christian Day’s last-gasp score secured a full five points for Northampton, who were 24-19 down as the clock struck 80.
Elliot Daly’s 60th minute try looked to have won it for Wasps, but Day came to the rescue for Saints as they beat their Premiership play-off rivals 26-24 at a freezing Adams Park.
Mallinder’s men had totally overpowered the home side during a first half in which they scored three tries from driving mauls.
But in the end it took Day’s late show and a Stephen Myler conversion to secure the points.
And Mallinder said: “We would have (kicked ourselves). I spoke with (forwards coach) Dorian West after about 65 minutes and we said the same sort of thing.
“It was a game we controlled. The forwards, particularly the maul, was exceptional, but a team like Wasps can score very quickly.
“Their tries came from a couple of our mistakes, but also our ill discipline and we gave away too many penalties to allow them to keep the scoreboard ticking.”
The victory at Adams Park was Saints’ fourth in succession and eighth in a row against Wasps.
It puts them four points ahead of fifth-placed Gloucester and seven clear of Wasps in the race for a top four spot.
And Mallinder said: “We’ve been going quite well. We were on a three-game winning run and you never know how the LV= Cup will affect that so it was really good to come here and get the win and bonus point.
“It puts us in a good position with four games to go.”