All-rounder Graham Napier starred with bat and ball, but Northamptonshire had the better of the opening day in their LV= County Championship Division Two clash with Essex.
After being asked to bat, the visitors were bowled out for just 183 at Northampton with Napier's explosive 73 not out off 65 balls, including five sixes, the only resistance as Steven Crook took 4-39.
Napier then claimed 3-30 as Essex clawed their way back into contention by reducing Northants to 156 for five at the close, captain Stephen Peters top-scoring with 60 off 92 deliveries.
Having opted to bowl, Peters was relieved when Andrew Hall’s introduction produced the first wicket in the 14th over; Rob Quiney was trapped lbw for 25.
Five overs later, Ben Foakes departed when he edged Crook to wicketkeeper David Murphy, who then held on to oust Tom Westley for 30 after Trent Copeland had located the edge.
Two wickets fell in four balls just before lunch as Mark Pettini was taken by Copeland at third slip off Crook before the same man bowled captain James Foster.
Things went from bad to worse in the second over of the afternoon as Ravi Bopara tentatively nudged at Murphy, giving Crook his fourth wicket.
David Willey got in on the act by having Greg Smith taken behind and bowling Maurice Chambers before Reece Topley was castled by Hall.
Napier hung around to complete his half-century off just 58 balls and created further carnage thereafter, only for Essex's innings to end when Tymal Mills hit Willey to Rob Newton at gully.
Napier struck in the eighth over of Northants' reply when Kyle Coetzer edged his delivery to Westley at second slip.
Four balls later, David Sales chipped Napier to Chambers at midwicket with Alex Wakely following him by tamely picking out Bopara at square-leg off Chambers.
Peters did his all to stabilise Northants' innings by going past 50 off 76 deliveries but perished when Pettini took a good, low catch at slip off Topley.
Hall then became the 15th wicket to fall on a frenetic day's play when he edged Napier to Pettini at first slip.