|LV County Championship Division Two, Northampton|
|Close, day three: Essex 433 & 26-0, Northants 538-9 dec|
|Essex 7pts, Northants 8pts|
Niall O'Brien and Chaminda Vaas both fell just short of centuries as Northants made Essex toil on day three at Wantage Road.
Both men made 96 and shared a seventh-wicket stand of 155.
With Lee Daggett (33) also contributing, Northants were able to declare on 538-9, a lead of 105.
Billy Godleman and Alastair Cook took Essex to 26-0 at the close, but the visitors will need to bat long into the final day in order to avoid defeat.
Resuming on 256-4, 177 behind, Northants lost Alex Wakely and Andrew Hall before O'Brien and Vaas combined.
They were parted when O'Brien smashed David Masters to cover, with Vaas then receiving good support from James Middlebrook (18) and Daggett.
The Sri Lankan eventually holed out to deep square-leg off Tim Phillips, with the Northants declaration coming soon after.
DAY THREE REACTION
BBC Essex's Nick Gledhill:
"After a good first hour Essex, armed with a non-swinging second new ball, found it tough going at Wantage Road.
"For Reece Topley in particular it was an education in coping with unresponsive conditions. Lonwabo Tsotsobe will be hoping for pitches more in his favour in the coming weeks.
"This remains a good wicket and Essex should save the game comfortably but Northants have today provided further evidence of their strength in depth in batting. This could be one of their best seasons in recent years."