Worcestershire 284 and 127 for 8 (McIlroy 4-27) lead Glamorgan 170 (van Beek 4-42, Pennington 3-43) by 241 runs

McIlroy returned career best figures of 4 for 27 from 11 overs to revive his side's hopes in the top three encounter in which 18 wickets fell on the second day.

Worcestershire will resume with a lead of 241 on a wicket still offering assistance and encouragement to the seamers. But the game is much more in the balance than had appeared likely when they reached 81 for 1 before a spell of losing seven wickets for 40 runs.

Jake Libby and Azhar Ali consolidated Worcestershire's position during the early part of their second innings against a Glamorgan attack handicapped by the absence of seamer Timm van der Gugten with a hamstring injury. But their depleted resources stuck to their task during a marathon 50-over final session and most notably McIlroy who picked up the first four wickets and ended the day with 12-3-27-4.

Glamorgan resumed on three for nought on a blistering hot day and Worcestershire's leading wicket-taker Joe Leach struck two early blows to take his first class tally for the season to 43.

The second ball of the morning accounted for Ed Byrom who pushed forward and Adam Hose snaffled the opportunity away to his right at first slip. Former Worcestershire Academy player Zain-ul-Hassan departed after a similar stroke with keeper Gareth Roderick accepting the chance.

Leach's new ball partner Pennington got in on the act as nightwatchman James Harris went lbw to a delivery angled in to leave Glamorgan on 27 for 3. It was a similar scenario to the opening day when Worcestershire lost three wickets for 33 on a pitch still offering enough encouragement to the bowlers.

Sam Northeast survived a straightforward chance at midwicket off van Beek but added only two more before he prodded at a delivery from Pennington and was pouched by Libby at third slip.

Van Beek picked up his maiden Championship wicket for Worcestershire when Colin Ingram drove hard and Libby again made no mistake.

Kiran Carlson experienced a difficult time, surviving two hard chances and being hit on the helmet by a short ball from Pennington. But the first over after lunch brought about his downfall as he took one hand off the bat and slapped on-loan Essex seamer Ben Allison to cover.

Chris Cooke and Billy Root then featured in the only substantial partnership of the innings in adding 62 in 14 overs before the last four wickets fell for 21 runs. Van Beek ended their resistance when Cooke was caught behind off an away swinger and in his next over Ben Kellaway perished at second slip.

Van der Gugten, who needed a runner, departed in the same manner off Pennington before McIlroy was yorked by van Beek to wrap up the innings.

When Worcestershire batted, Roderick was caught by keeper Cooke off the first ball of the innings from McIlroy.

Libby and Azhar then joined forces and saw off the new ball before their partnership flourished in relatively untroubled fashion. But McIlroy returned to the attack to pick up three wickets in the space of 13 balls to spark a substantial collapse.

Azhar provided Cooke with another scalp after attempting to cut to end a stand of 81 with Libby. McIlroy had more joy when Libby was undone by a ball of extra bounce which he nicked to at first slip. Jack Haynes then drove at McIlroy and second slip did the rest.

Hose shouldered arms and was bowled by Harris, Zain trapped Kashif Ali lbw and then castled van Beek after he also offered no stroke. Harris took the final wicket of the day when he beat the defensive push of Allison.