England Under-19 wicket-keeper Joe Clarke top-scored in his first Second Eleven Championship appearance of the season for Worcestershire against Glamorgan at Kidderminster.
The 18-year-old made 71 off 125 balls with seven fours and a six and shared in a sixth wicket stand of 73 with George Rhodes whose 56 from 112 deliveries contained seven boundaries.
But from 225-5 the last five wickets fell for 42 runs to give Glamorgan a first innings lead of 142.
The other substantial stand was 66 between openers Shaaiq Choudhry – 62 off 73 balls with 10 fours – and Alex Hepburn.
Glamorgan built on their healthy advantage in reaching 198-2 by the close – a lead of 340 with one day remaining.
Veteran Murray Goodwin hit an unbeaten 91 off just 77 balls with 14 fours.
Worcestershire first innings (overnight 38-0): Hepburn c Knight b Owen 12, Choudhry c Lancefield b Carey 62, Oliver b Owen 0, Clarke b Carey 71, Andrew b Bull 12, D'Oliveira b Bull 24, Rhodes lbw Carey 56, Williams c Brown b Carey 2, Cessford c and b Bull 12, Harrison c and b Brown 7, Whiles not out 0, Extras 9. Total 267 all out (76.1 overs).
Bowling: Owen 2-48, Bull 3-71, Brown 1-77, Carey 4-23.
FOW: 66, 66, 92, 124, 152, 225, 241, 248, 267, 267.
Glamorgan second innings: Lancefield c Andrew b Choudhry 24, Rees c Andrew b Williams 57, Goodwin not out 91, Walters not out 21. Extras 5. Total 198-2 (38 overs).
Bowling: Whiles 6-1-30-0, Cessford 10-2-45-0, Harrison 7-1-22-0, Choudhry 5-0-32-1, Rhodes 4-0-37-0, D'Oliveira 2-0-12-0, Williams 4-0-15-1.
FOW: 50, 146.
