Century-makers Chris Dent and Alex Gidman put Gloucestershire in control on the opening day of their LV= County Championship Division Two game against bottom-of-the-table Kent.
The pair came together at 74-2 in the 19th over and put on 267 for the third wicket as the hosts reached 348-3 at stumps.
Dent hit his first hundred of the season from 205 deliveries and advanced to a career-best 153, with 17 fours and two sixes in his 270-ball innings, before Calum Haggett had him caught behind.
Gidman, who survived difficult catching chances on 38 and 58, brought up his third County Championship century of the year from 185 balls and moved on to 145 not out at stumps, having struck 19 fours and a six.
After winning the toss, home skipper Michael Klinger helped Dent get the innings off to a brisk start with a flurry of boundaries from the bowling of South African star Vernon Philander and Charlie Shreck.
Haggett made the breakthrough for the visitors in his second over from the College Lawn End. Klinger chased a wide delivery and only succeeded in edging it to Darren Stevens at second slip to depart for 20 with the score on 46.
Haggett, who was released by Somerset without making a first-class appearance, struck again in his fifth over when Dan Housego, on 13, got an inside edge onto his stumps.
Gidman enjoyed a slice of luck on 38 when Brendan Nash failed to grasp a head-high chance at extra cover off Stevens. His second reprieve came on 58 when Stevens, at backward point, failed to hold a diving catch off Philander.
Dent also offered a chance on his way to three figures. The left-handed opener flicked the third ball after tea from Shreck down the legside, but wicketkeeper Geraint Jones was unable to hold a one-handed diving catch.
The pair accelerated the scoring rate in the closing hour's play before Kent finally had a third wicket to celebrate when Haggett struck with four overs of the day remaining as Dent flashed at a ball outside off stump and snicked a catch to Jones.