|LV= County Championship Group Three, Sophia Gardens, Cardiff (day three):|
|Glamorgan 285: Carlson 127*; Robinson 4-50 & 258-5: Carlson 129*; Robinson 4-59|
|Sussex 481: Van Zyl 113, Garton 97; Hogan 4-46|
|Glamorgan (4 pts) lead Sussex (8 pts) by 62 runs|
Sussex seamer Ollie Robinson put his team in the driving seat before Kiran Carlson's second hundred of the match for Glamorgan took the game into the final day.
The home side, on 258-5, lead by just 62 runs in Cardiff.
Carlson's 129 not out made him the first Welshman to double up for Glamorgan in 16 years.
But Sussex still remain favourites to complete victory with the weather set fair in Cardiff.
Robinson took 4-59 to add his his first innings 4-50 as he benefitted from a string of leg-before decisions, the umpires giving 15 so far in the match.
He exposed the problems of the Glamorgan top order with the first three wickets falling for fewer than fifty in every innings this season.
Carlson flew to his century in 116 balls with 16 fours, eventually adding 108 with Callum Taylor (33 not out) although the pair were bogged down by some accurate spin in the evening sun from off-spinner Jack Carson, 20, and left-armer Delray Rawlins.
Earlier Glamorgan took just three balls to finish the Sussex first innings as Michael Hogan trapped Robinson lbw for 67, his innings contributing to a fine all-round performance from the recent England winter tourist.
Play was halted for 80 minutes during the funeral of HRH Prince Philip, Duke of Edinburgh, with the teams, staff and umpires observing a minute's silence on the outfield.
Glamorgan captain Chris Cooke told BBC Sport Wales:
"It was a pretty good day for us, and Kiran's played unbelievably well and given us a bit of hope so we just have to keep fighting.
"It's about having a positive game plan which Kiran has done all season, it can be diffcult to score at times but you've got to stick in and you will get your rewards.
"Kiran deserves all the accolades, he's worked really hard this winter after he batted three last year and got a few good balls, but he's come back really strongly and he's looking the real deal.
"How long we need to bat depends how quickly we score, we'll be looking to the first hour and go from there."
Sussex coach Ian Salisbury told BBC Radio Sussex:
"Rationally, statistically they're 62 for five, a great game of cricket and well played to the young man (Carlson), he was sensational and we haven't got him out yet in the match.
"We didn't expect them to roll over but I'd settle for (Glamorgan being effectively) 62 for five going into the final day.
"Ollie is an outstanding bowler and has proved that now for a few seasons, so if he wants to play for England he's got to keep up performances like that and I'd say he looks Test match standard."