Bowling coach Phil Rowe was delighted with the performance of his players as Northants enforced the follow-on against Middlesex.
The County took control on the second day of the Specsavers County Championship Division Two clash, bowling Middlesex out for 187 in the first innings.
Nathan Buck bagged four for 51, Rory Kleinveldt took three for 20 and Ben Sanderson secured two for 31.
Sanderson then struck again early in the second innings as Middlesex finished the day on 32 for one, 127 behind Northants' first innings total of 346.
And Rowe said: “We’re really pleased, we learned from the first innings, pitched the ball up a little more and talked about hitting the stumps a lot.
“It was a pretty relentless stuff and the lads supported each other well.
"Nathan is someone who doesn’t always get his rewards so it was nice to see him pick up four.
“The decision to follow-on was unanimous. We hadn’t got through too much work - the most-bowled bowler had only sent down 16 - and they were loose and going well so we’ve tried to take them out of the game as soon as we could.”
Middlesex will have a fight on their hands to stay in the game on day three.
And their wicketkeeper, Robbie White, said: “It did quite a lot yesterday (Sunday) as well and we portably let them off the hook and got quite a few more than par.
“We’ve been fighting from behind and we’re a bit light with the bat as well.
“We got off to a great start and had a wobble but getting together with Max (Holden) was good to knuckle down but it was frustrating to do the hard work and then couldn’t quite get past the follow-on."