An unbeaten century from Chris Dent and a career-best 88 not out from nightwatchman Liam Norwell ensured Gloucestershire dominated the third morning of the Specsavers County Championship match with Derbyshire at the Brightside Ground, Bristol.
Resuming on 110 for one in reply to 444, the second-wicket pair batted positively throughout the session to move their side onto 254 for one at lunch.
Dent reached his ninth first class century off 154 balls, with 14 fours and a six, while Norwell, who averaged 8.3 in 19 Championship innings last season, eclipsed the 78 he made against Worcestershire at Cheltenham in 2014.
The Derbyshire attack was toothless on a benign wicket and neither batsman gave a chance. Norwell reached his second first class fifty off 70 balls, with 8 fours and a six.
Dent was unbeaten on 106 at lunch, with the partnership worth 152.