Alex Gidman's career-best 211 and Hamish Marshall's 106 guided Gloucestershire to an imposing 562 for five declared on the second day of the LV= County Championship game against Kent at Cheltenham.
But Gloucestershire's attack also found bowling on the placid College Ground pitch an equally arduous task as Kent reached 165 for two at stumps, thanks largely to an unbeaten 79 from Sam Northeast and 57 from Rob Key.
Gidman, who started the day on 145, improved his previous best score of 176, made versus Surrey at Bristol in 2009, and went on to become Gloucestershire's first double-centurion since Craig Spearman achieved the feat against Warwickshire at Bristol in 2004.
He was eventually run out by Brendan Nash's underarm throw from mid-on, having put on 168 in 41 overs with Marshall for the fourth wicket. His seven-hour innings came off 347 balls, contained 25 fours and two sixes and he has now scored 894 runs this summer at an average of 74.5.
Gloucestershire resumed on 348 for three, and Gidman and Marshall added 140 in the morning session in largely untroubled fashion.
The closest Kent came to claiming a wicket was when Gidman, needing one more to pass his career-best, was nearly run out after Marshall called for a quick single to cover.
Gidman took a single off James Tredwell to bring that landmark up and showed no sign of nerves as he approached a double-hundred.
He hit James Tredwell for a straight six to move into the 190s and then carved Ben Harmison to the backward point boundary to reach 199. A single to midwicket off Harmison's next delivery brought Gidman his 334-ball double-century, which contained 24 fours and two sixes.
Gidman added one more boundary after lunch before he called for a single to mid-on off Charlie Shreck and was beaten by Nash's direct hit.
There was no respite for Kent, though, as Marshall and Benny Howell plundered 53 in seven overs for the fifth wicket.
Howell took 16 off one over from Shreck, including a pulled six over square-leg, and was unbeaten on 34 from 23 deliveries when Marshall's dismissal brought the declaration from skipper Michael Klinger.
Marshall had reached his third century of the summer with a single to cover off Harmison and had moved onto 106, with 12 fours and a six, when he holed out to Calum Haggett on the midwicket boundary, which gave Tredwell his first championship wicket of the summer.
Bat continued to dominate ball as Northeast and Key took Kent to 61 without loss at tea with few alarms.
But it was not quite so comfortable for the batsmen in the final session as Will Gidman put everything into an excellent spell from the College Lawn End, while on-loan Middlesex spinner Tom Smith posed a few problems from the Chapel End.
Key reached his half-century from 94 balls, but was undone soon after when he pushed forward to Will Gidman and nicked a low catch to wicketkeeper Gareth Roderick.
Northeast, who had survived a sharp caught and bowled chance to James Fuller on 38, brought up his 86-ball half-century with a midwicket boundary off Smith.
However, Gloucestershire did have one more wicket to celebrate as Daniel Bell-Drummond was bowled by Howell for 21 with four overs of the day remaining.