JIM Allenby struck a County Championship personal best score of 138 not out as Glamorgan took total control of their Division Two clash against Leicestershire on day two.
The all-rounder's unbeaten century formed the foundation for the Welsh county's first innings of 442 for nine declared, their best of the season so far.
It was then left to Glamorgan's seamers Michael Hogan and John Glover to turn the screw on the hosts, taking four wickets apiece to dismiss the Foxes for 142 and a lead of 300 runs.
Having lost their last two LV= County Championship matches against Lancashire and Essex, Glamorgan are now in a commanding position to register their second victory of the summer. Resuming on 256 for five, Glamorgan set the tone for a dominant day with an excellent first session, scoring 125 runs for the loss of just one wicket.
The innings was held together by Allenby's 204-ball knock, and he was ably supported by Graham Wagg, who made 58 before a couple of quick wickets prompted Glamorgan to declare on 442 for nine.
Matthew Mott's men then made a strong start with the ball, as Australian fast bowler Hogan had Greg Smith caught by Allenby for 11 in the third over.
Leicestershire lost their second wicket just seven balls later, when Michael Thornley was out leg before to John Glover. Hogan then claimed his second scalp when Ned Eckersley was caught by Murray Goodwin for four, and Leicestershire went into the tea interval on 41 for three.
Wagg got in on the act soon after the restart, dismissing Shiv Thakor thanks to a catch from Marcus North.
That left Leicestershire teetering on 44 for four, and it only got worse for the home side as Hogan struck to remove Joe Burns leg before in the next over.
While Hogan ran riot from one end, Glover was doing so at the other. Matthew Boyce top-scored for Leicestershire with 29, but Glamorgan's seam duo polished off the hosts' tail to bowl them out for 142 at the close, giving them a 300-run cushion ahead of their second innings.
Dafydd Pritchard