Surrey seamer Chris Tremlett took six wickets on day two of their County Championship Division Two clash with Gloucestershire to tilt the game at the Kia Oval in the hosts' favour.
Sixteen wickets fell on day one and that trend continued on Monday as the visitors took Surrey's final four first-innings wickets for just 14 runs to give themselves a slender lead of 36.
But Tremlett came to the fore to skittle through the Gloucestershire order, ending with figures of 6-59 as Surrey took all 10 wickets for 230 - leaving them chasing 267 for their first victory of the new season.
Captain Graeme Smith led the charge for the hosts as he ended the day on 34 not out, with his side requiring 226 runs to win heading into day three with all 10 second-innings wickets intact.
Doug Bollinger and Darren Stevens took five wickets apiece as Derbyshire were dismissed for just 118 after their home clash with Kent finally got under way on day two.
Following a washed out first day on Sunday and further wet weather on Monday morning, play began just after 2.30pm - but Derbyshire must have soon been wishing the delay had lasted even longer.
The hosts, inserted by their opponents, were quickly in trouble as they slipped to 24-3, which, after another rain interruption, became 57-5.
And they subsequently lost their last five wickets for just 15 runs, with Australian paceman Bollinger and veteran all-rounder Stevens finishing with figures of 5-29 and 5-24 respectively.
Kent then closed a good day for them on 10 without loss, Sam Northeast (9no) and captain Rob Key (1no) the men at the crease.
Hampshire look on course to establish a handsome first innings lead at stumps on day two of their match with Glamorgan at the Ageas Bowl.
Hampshire lead by 106 runs with two wickets remaining in the first innings after a rain-affected second day's play.
Michael Carberry led the scoring with 66, Liam Dawson reached 64 and James Vince 61 while Michael Bates (22 not out) and Kyle Abbott (17no) guided the hosts to the close.
Jim Allenby and Graham Wagg finished the day with three wickets apiece as Glamorgan's bowlers got on top late in the day.