Matthew Maynard shared in Glamorgan's biggest stand of the season and wrestled back the initiative from Northamptonshire on the third day at Sophia Gardens.

The former skipper, 36, blasted his way to 151 from just 150 deliveries to turn the match on its head by putting on 252 for the second wicket in partnership with fellow centurion David Hemp.

By the close Glamorgan had reached 470 for five for a lead of 388, after beginning their second innings staring at an 82-run deficit.

Maynard clubbed two sixes off Mathew Inness, and took four successive boundaries in one over off Matt Cassar to total 19 boundaries along the ground.

Hemp faced 136 balls for his 108 - he struck 20 fours - to help lift the Welshmen from 23 for one to a commanding 275 for two.

Glamorgan's previous best partnership for the season was 217 between Maynard and Adrian Dale against Nottinghamshire last month.

And it was left to the part-time leg-spin of Rob White to break the mammoth stand, Hemp bowled through the gate and Maynard stumped by Tobin Bailey 11 balls later.

Dale and Mike Powell then shared in an 89-run stand for the fourth wicket, the former hitting 10 fours in a 75-ball 50.

Powell had moved onto an undefeated 82 - he faced 133 deliveries - and Robert Croft was not out on 43 from 62 balls at the close.

Earlier, Northants' Tony Penberthy had finished unbeaten on 130 as he saw his side add 21 runs to their overnight 409 for eight.

Darren Thomas completed a five-wicket haul with the wickets of tail-enders Mathew Innes and Jason Brown.

Glamorgan: M P Maynard, M A Wallace (Wkt), D L Hemp, M J Powell, A Dale, J Hughes, R D B Croft (Capt), S D Thomas, D S Harrison, A P Davies, D A Cosker.

Northamptonshire: R A White, M J Powell, D J G Sales, J W Cook, M E Cassar, A L Penberthy (Capt), T M B Bailey (Wkt), G L Brophy, C G Greenidge, M W H Inness, J F Brown.