John Glover led some late Glamorgan batting aggression to put his side in a dominant position at the end of the third day of the LV= County Championship match with Hampshire at the Ageas Bowl.
Glover, who had hit only one previous half-century in his career, struck eight fours in an unbeaten 51 before his captain Mark Wallace declared with Glamorgan 129 ahead at 478-9 in their first innings.
In the 41 overs which remained Hampshire lost openers Jimmy Adams and Michael Carberry in making 115-2, still 14 behind and with a day left.
The visitors went into the third day at 226-4, still trailing Hampshire by 123, but they soon made up the deficit on their way to a healthy lead of their own on a pitch still offering little support to the bowlers.
Chris Cooke, 73 not out, and Jim Allenby made their fifth wicket stand worth 127 before Allenby edged Sohail Tanvir to Liam Dawson at slip when the score was 297.
Cooke, eight runs short of his maiden first-class century, was dismissed in the next over, also caught at slip by Sean Ervine off Chris Wood.
Cooke, whose previous best had been a modest 44, hit 16 fours which hinted at his promise and faced 153 balls but his exit only hastened some lower order hitting by Graham Wagg, who made 33, Wallace, Dean Cosker and above all by Glover.
Hampshire ran out of ideas in the heat of the Southampton afternoon as Wallace and Cosker each gleaned 39 while the belligerent Glover took the attack to the tiring bowling.
In the end opening batsman Will Bragg, who made five, was the only Glamorgan batsman not to reach double figures and the declaration came with number nine batsman Glover reaching his creditable landmark.
Glamorgan's lead began to look formidable as Adams departed at 20, deceived by Cosker's turn, and then Carberry departed at 102 after a second-wicket partnership of 82 with Liam Dawson.
Carberry at least had the satisfaction of reaching 10,000 career runs in first-class matches while making 62 but his departure to Wagg's medium pace lifted Glamorgan beliefs that their second county championship win could be on the way at last.