Trent Copeland continued his excellent form with the ball by taking seven wickets on the third day of Northamptonshire's clash with Leicestershire.
Northants' Australian international returned outstanding figures of seven for 63 as Leicestershire were bowled out for 234, teenager Shiv Thakor top-scoring with an unbeaten 64 off 96 balls.
A late flurry of wickets saw Northants close on 94 for five, giving them a lead of 215, with the impressive Ollie Freckingham taking three for 28 to add to his six first-innings dismissals.
Leicestershire began the day on 89 for one, 266 runs behind their opponents, with opener Greg Smith resuming on 36 and Ned Eckersley on 16. Smith went on to complete a fluent half-century off 77 balls but he departed cheaply on 51 when smashing Copeland straight to Matthew Spriegel at point.
After a couple of brief delays for bad light and rain, Copeland removed Eckersley for 25 when he trapped him lbw before Josh Cobb went for a two-ball duck when David Willey uprooted his off stump. Leicestershire suffered another blow with the final ball before lunch when they lost captain Ramnaresh Sarwan (19), lbw to Copeland, to leave them on 134 for five.
Copeland completed his third five-for in consecutive Championship innings and eighth overall in first-class cricket when Matthew Boyce chopped on to his stumps to perish on 23 and continued to tear through the Leicestershire batting order when he had Jigar Naik (two) caught leg before. Willey then repeated the trick to Freckingham (five).
Robbie Williams faced two balls without scoring before edging Andrew Hall to Northamptonshire wicketkeeper Ben Duckett, but 19-year-old Thakor stuck around to go past 50 off 85 deliveries before Copeland finished off Leicestershire's innings when he trapped Alex Wyatt lbw for a single.
Looking to build on a first innings lead of 121, the hosts lost Spriegel for just one in just the third over - yet another lbw victim with Freckingham taking his wicket.
After an hour-long delay for bad light, Northamptonshire lost David Sales for 31 when he was well taken by Leicestershire wicketkeeper Niall O'Brien off Wyatt.
Two wickets fell in the penultimate over as James Middlebrook edged Freckingham to O'Brien on 43 before Rob Newton senselessly smashed the same man to Eckersley at mid-on.
Northamptonshire's sloppy end also saw their captain Alex Wakely (12) walk when he edged Wyatt to Smith at second slip with the final ball of the day.