Division Two leaders Northamptonshire took complete control on the second day of their LV=County Championship clash against Gloucestershire at Bristol.
Half-centuries from Alex Wakely, James Middlebrook and Steven Crook helped the visitors run up a healthy 404 all out in reply to 192.
Gloucestershire were left with an awkward period to bat before the close and lost skipper Michael Klinger for a single in moving to 3-1, still 178 runs behind.
Beginning the day on 107-3, Wakely top-scored for the leaders with 88, while Middlebrook made 62 and Crook 53.
Rob Newton was first out, quickly adding to his overnight score of 14 before being caught at backward-point by Jack Taylor off Benny Howell for 39 to make the score 149-4.
Wakely, unbeaten on 23 overnight, was joined by Andrew Hall and the pair moved the score onto 227 when Hall fell leg-before to Will Gidman for 28.
That became 242-6 when Wakely departed, also lbw to Gidman, and Northants slumped to 283-8 when David Payne took two quick wickets with the new ball.
First, David Murphy was caught by diving wicketkeeper Cameron Herring for 16 and three balls later David Willey had his middle stump uprooted.
The visitors' lead was just 91, but their tail wagged energetically as Crook joined Middlebrook to produce the most attacking batting of the day to take the game away from the hosts, as well as ensuring Northants claimed maximum batting points.
Gidman was the pick of the Gloucestershire bowlers, finishing with 4-109 off 28 overs, but his side still have a mountain to climb.