Worcestershire edged closer to their third LV= County Championship win of the season as Glamorgan continued to take a pounding in the Division Two fixture at New Road.
At the start of the third day the home side needed 15 wickets for victory and by the close they had taken all but three of them with Glamorgan still 28 short of avoiding an innings defeat.
Resuming on 164-5, Jim Allenby propped up the Welshmen with 82 in their first innings dismissal for 277 and weighed in with an unbeaten 53 when they batted again, trailing by 228.
Worcestershire's seamers maintained relentless pressure on a largely unresponsive surface and weather permitting they can now expect a quick wrap-up when the visitors begin the final day on 200-7.
Fast-improving Jack Shantry led the Worcestershire charge with 8-132 in the match and Alan Richardson became the leading wicket-taker in the country when claiming his 40th victim of the summer.
For Shantry it was a continuation of an impressive sequence on his home ground. Having posted a championship-best 7-69 in the last home match against Essex, he has now taken 15 wickets in three innings at county headquarters.
Glamorgan were simply overwhelmed by the pressure of replying to a massive total of 505-7. There was just a glimmer of hope on the third morning when Allenby and Mark Wallace took their sixth-wicket stand to 114 but there was little to come when Worcestershire won three leg before wicket decisions in 10 balls.
Alllenby was the first for young all-rounder Joe Leach and there was a final flourish by Wallace (43) and Michael Hogan, with 37 from 42 balls, before Shantry mopped up the last two wickets.
Although Glamorgan's second innings was twice interrupted by rain, their batting was again fragile before a tiring attack was unable to make the final push as Will Owen (34 not out) joined Allenby in putting on an unbroken 71 in the last 15 overs.