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 for nine in their first innings.
In the 41 overs which remained Hampshire lost openers Jimmy Adams and Michael Carberry in making 115 for two, still 14 behind and with a day left.
Both sides are in desperate need of a win, Glamorgan having won once in 10 Division Two fixtures and Hampshire twice.
Glamorgan went into the third day on 226 for four, trailing by 123, but they soon made up the deficit on their way to a healthy lead on a pitch still offering little support to the bowlers.
Chris Cooke 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 just as a big opportunity beckoned.
The youngster, whose previous best was 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, 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 Hampshire 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 with the score 102 after a second-wicket partnership of 82 with Liam Dawson.
Carberry at least had the satisfaction of reaching 10,000 career first-class runs while making 62 but his departure to Wagg's medium pace lifted Glamorgan belief that their second win this term could be in the pipeline.