Gloucestershire 62 for 3 trail Glamorgan 220 (Selman 101, Miles 4-44, Taylor 4-56) by 158 runs
Glamorgan would have been in deep trouble had Australian born Nick Selman not scored 101, almost half the team's total, in an attacking innings.
Selman, who last month carried his bat for an undefeated hundred against Northants, looked as if would emulate that performance until he was bowled the delivery after reaching his century. He will hope that this innings will not start a run of poor form- following his first century he suffered a run of four ducks.
After an uncontested toss, Mark Wallace - in the absence of Jacques Rudolph, who had a sore neck - opened the innings with Selman, but Wallace was out in the seventh over, leg before to David Payne, which prompted a spectator to shout behind the arm" that was a poor decision umpire".
Selman had started with a flurry of boundaries, and although Will Bragg and David Lloyd were both out cheaply, Glamorgan had reached 130 for 3 at lunch, with Selman and Aneurin Donald in full flow.
The fourth wicket pair had put on 65, before Donald, who was only four runs short of his 1,000 first-class runs for the season, top-edged an intended pull to mid-on. Kieran Carlson, playing his second championship game, was out with scoring, and after Selman was dismissed, Craig Meschede was also dismissed by Matt Taylor.
Graham Wagg, meanwhile, played a watchful innings on a pitch that was seamer friendly, and had to contend with some accurate bowling from the Gloucestershire seam quartet. Wagg and Timm Van Der Gugten added a useful 38 for the ninth wicket, enabling Glamorgan to gain a batting point, before they were both dismissed by Craig Miles who, with Taylor, took four wickets.
Gloucestershire had to face 31 overs after tea, but soon lost Gareth Roderick who edged Van Der Gugten's fifth ball to second slip. The Glamorgan seamers also bowled a tight line, but it was a short delivery that undid Chris Dent, who tamely guided the ball to square leg.
Will Tavare, who had laboured 67 balls for his 18, was the next to go when he was lbw to Michael Hogan, who was leading Glamorgan in Rudolph's absence. Hamish Marshall and George Hankin, who was the Player of the Tournament in the recent Under-19 series against Sri Lanka, guided Gloucestershire to the close at 62 for3, a deficit of 158.