Glamorgan 125 for 4 (Agar 3-29) trail Kent 155 (Bell-Drummond 55, van der Gugten 3-27, Harris 3-35) by 30 runs
Kent collapsed with six wickets falling for seven runs on the opening day against Glamorgan at Sophia Gardens.
Daniel Bell-Drummond top-scored with 42 in a day dominated by bowlers, despite the use of the Kookaburra ball as 14 wickets fell on day one. Kent fell to 155 all out from 148 for 3 with Joe Denly retiring hurt, pulling a muscle playing a shot during his innings.
Timm van der Gugten and James Harris provided rewards for Glamorgan with 3 for 27 and 3 for 35 respectively with the older ball before Wes Agar responded in kind with the new ball, ripping into the hosts' top order with 3 for 29, restricting Glamorgan to 125 for 4.
Despite the often favoured chance to keep the opposition in the field for as long as possible during rounds using the Kookaburra ball, Glamorgan opted to field first under overcast skies.
Ben Compton and Jadyn Denly dealt nearly exclusively in boundaries for their 37 before Asitha Fernando struck - the division's top run-scorer, Compton, caught behind - a first wicket on the Sri Lankan's return to Glamorgan for a second spell this season.
Unconverted starts continued to be the frustration for Kent. Denly dispatched loose Harris deliveries on his introduction into the attack before slapping another to cover.
Notwithstanding Denly's injury, Kent added 61 for the third wicket before Ben Kellaway found a way through Chris Benjamin, adjudged lbw.
From 111 for 2 at lunch and Bell-Drummond reaching 24 in minimal time thanks to four consecutive boundaries off Ned Leonard, the approach was forced to change by Kent with the hosts tightening their bowling.
Glamorgan's revived efforts with the ball started the monumental collapse. Joey Evison flashed at a wide delivery to give van der Gugten his first wicket of a six-over spell in which he conceded just two runs.
It wasn't long afterwards that Kent were getting their whites on to take the field. Bell-Drummond was next to be adjudged lbw off an in-swinger from Harris. Two in two balls came for van der Gugten, before Zain Ul Hassan and Harris finished the job to leave the number eight Stewart stranded, Joe Denly unable to return.
With an opportunity in the 42-over final session to close in on a lead before the end of day one, Glamorgan quickly learnt that the task to overtake 155 wasn't as easy as first thought.
Asa Tribe looked troubled from the off before he inevitably chopped on to get Kent underway through Agar. Ul Hassan was more dogged in his approach, as has been his method since bedding in at the top of the order. He stuck around after the dismissals of Carlson and Root before perishing himself for 27.
Carlson appeared still to be in Vitality Blast mode, with five fours in his 25-ball 27 before loosely driving to his downfall, caught behind. Billy Root, making his first red-ball appearance of the season, never settled.
On the day 40-year-old Colin Ingram was announced to have a first coaching role, the veteran was still showcasing his playing abilities, taking a four and six from the same Evison over. The South African and Kellaway remained unscathed despite periods of concern and grit, including Ingram dropped on 27 late in the day, closing out the long session with a much-needed unbeaten partnership worth 47.
