|LV County Championship Division One, Bristol|
|Close of play, day two: Northants 557-9dec, Gloucestershire 172-7|
|Northants 7pts, Gloucestershire 2pts|
James Middlebrook hit his second County Championship century of the season as Northants dominated on day two against Gloucestershire at Bristol.
Resuming on 381-6, Middlebrook helped extend his overnight seventh-wicket stand with Niall O'Brien to 187.
O'Brien finally went for 166, but Middlebrook stayed on to hit 109 as Northants declared on 557-9.
Gloucestershire then limped to 172-7 by the close, still needing another 236 runs to avoid the follow-on.
Middlebrook's highest score for his new county helped the visitors establish an iron grip.
But it could have been even worse for Gloucestershire, who at one stage slipped to 31-5 after Jack Brooks (4-30) took three wickets in the space of seven balls.
Former skipper Chris Taylor (54) and current captain's brother Will Gidman (72 no) led a spirited recovery with a stand of 115.
But the hosts still trail by 385 runs with just three first innings wickets remaining.