Worcestershire Seconds fought back strongly with the ball on a rain-curtailed second day in the Second Eleven Championship match with Glamorgan at Newport.
Glamorgan stood on 442-1 at one stage but then lost eight wickets for 85 runs in the space of 25 overs with three of them falling to Cameron Jones.
It earned the home side a first innings advantage of 188, still significant but not as sizeable as had seemed probable at one stage.
Worcestershire openers, Tom Fell (21 not out) and first innings century-maker Taylor Cornall (10 not out), then safely negotiated 10 overs with the new ball in reaching 31-0 by the close.
Glamorgan resumed on 377-1 but with three changes to their side with Colin Ingram, Billy Root and Jamie McIlroy replaced by Thomas Bevan, Callum Nicholls and Ben Morris respectively.
Root retired not out on 175 and Ingram retired not out on 47 so two new batters were at the crease when play finally got underway at 3pm after overnight and morning rain.
Pat Brown bowled his third spell of the innings and had figures of 5-2-12-0 to add to his eight overs yesterday in his comeback from injury.
Jones made the first breakthrough of the day when Nicholls was undone by a delivery which was too full in length to cut and Taylor Cornall held a sharp chance at second slip.
Reeve Evitts had scored his maiden Seconds half century yesterday and enjoyed more success with the ball.
Callum Taylor (6) pushed forward and was bowled to earn Worcestershire a bowling point in the 94th over.
Three balls later Evitts broke through again as Morgan Bevans (0) edged a delivery which nipped away and was caught behind by captain and keeper, Gareth Roderick at 460-4.
A further flurry of wickets fell after tea.
Brown struck in the only over of his fourth spell as Thomas Bevan (55) top-edged a catch to deep backward square.
Cameron Jones, a recent addition to the Worcestershire CCC Academy, picked up two wickets in two balls with Tom Cullen (7) driving caught at first slip and Rhodri Smith (0) yorked by a fine delivery.
Luke Carey (17) had a heave at Roshan Balaji and was bowled in the 105th over but the dropping of a straightforward chance denied Worcestershire the maximum three bowling points.
Dan Douthwaite (30) holed out to long-off against Mitchell Stanley to end the innings at 527-9 after 110.4 overs as Eddie Byrom was absent injured.
Jones ended with figures of 18-0-82-3, Evitts 11-3-34-2, Stanley 14.4-3-57-2, Brown 14-2-60-1 and Balaji 14-1-65-1.