Glamorgan 241 for 8 (Gill 92, Byrom 67) trail Worcestershire 454 for 9 dec (Roderick 172*, Leach 87, Barnard 75, Pollock 54, van der Gugten 4-81) by 213 runs
India batter Shubman Gill was the star performer between the rain breaks at Sophia Gardens, despite falling eight runs short of a century on debut as Worcestershire kept alive slim hopes of forcing victory.
Glamorgan still need 64 to avoid the follow-on target of 305, finishing on 241 for 8 thanks to Gill's classy 92 - falling lbw to Ed Barnard two balls before play stopped for bad light on a day when only 50 overs were possible.
Glamorgan were happy chasing the batting bonus points that would take them past the follow-on target and also potentially past Middlesex into second place in the table, with those two teams meeting next week at Lord's.
Worcestershire need a win to boost their chances of joining that promotion race, but that will take quite a turnaround given more rain is forecast in Cardiff on the final day.
There was a little under two hours of play possible before lunch, then a lengthy break before the players returned after tea for a truncated evening session with 44 overs having been lost and a further 10 because of bad light.
Gill had shown the previous evening that he was a different class to any other batsman on this pitch and picked up where he had left off by hitting his first ball through mid-on in classical fashion.
Nightwatchman Timm van der Gugten had a bit of fun before departing on 18 but, while the ball regularly went past the edge of the other batters, the speed of Gill's foot positioning meant he was comfortable against all the bowlers and hardly played and missed.
Sam Northeast would have been confident coming to the wicket on the back of breaking the Glamorgan county batting records in both red-ball and white-ball cricket, but an off-cutter from Dillon Pennington saw him depart for 10.
Worcestershire's hopes were well and truly raised when Pennington's next ball found the edge of Kiran Carlson's bat and Ed Pollock took the catch at slip to make it two wickets in two balls.
Billy Root has a good record against Worcestershire and he was able to avoid the hat-trick and then keep Worcestershire at bay until the rain came.
Resuming after tea, Glamorgan slipped deeper into trouble despite gaining their first batting bonus point of the game. Root was lbw aiming through midwicket to give Ben Gibbon his third victim.
Then came the big wicket of Gill, also lbw aiming through midwicket - this time Ed Barnard was the bowler. Gill will count himself especially unlucky as two balls after his departure all the players were walking off for bad light.
The players did return for a final 10 overs, James Harris being bowled by Pennington on what proved to be the last ball of the day.
Gill said afterwards that he had enjoyed his innings. "It was a great experience for me to come here and play county cricket and spend some time in the middle so it was a good outing for me today," he said. "The conditions are different to back home, especially with the rain - you stop, you start again, you stop, you start again, which is challenging when you are in the zone. It is also part of the experience when you play in the UK.
"They bowled some decent spells, hit some good areas. We should be able to give them a good competition in terms of saving the match. Our first target is to get over 250 and a batting bonus point, once we are over that then even if we follow on I think we could save the match.
"It is obviously disappointing to get out, it does not matter if it rains after that or not. And I was quite disappointed, especially to be out on 92, but I was pretty satisfied with my own performance because I wanted to spend some time out in the middle and I got that. Hopefully when I bat next for Glamorgan I will be familiar with the conditions."
