Northamptonshire were in charge for most of day one of their LV= Insurance County Championship match at Canterbury, until a mini-revival from Kent left them on 362 for five at stumps.
Emilio Gay hit 101, his maiden first-class century, while Luke Procter made 81 and Ricardo Vasconcelos 66 as Northants dominated until an hour after tea.
The new ball then helped bring Kent back into the Group Three game, Darren Stevens taking two for 52 and Matt Quinn two for 77.
Kent lost the toss for the seventh time out of eight this season and they were once again left to rue their luck as the visitors chose to bat, Vasconcelos and Gay exploiting a benign surface to put on 135 for the first wicket.
Kent bowled with some hostility but no real menace and the only breakthrough came in the 26th over when Quinn, having switched to the Nackington Road end, had Vasconcelos caught behind.
The visitors reached 141 for one at lunch and Gay continued to play with measured aggression after the break, passing his previous highest first-class score of 77 by hitting Marcus O’Riordan for six over long on. He reached three figures when he glanced Jack Leaning to square leg for two, but he was subsequently out to the same bowler without adding to his score, caught behind after slashing at a wide delivery.
Northants were 246 for two at tea and they eased to 314 without further loss before Quinn had Procter lbw in the 82nd over. Stevens then struck twice, luring Rob Keogh into an edge to first slip, where he was caught by Jordan Cox for 38, before sending Adam Rossington’s off stump flying in his next over, bowling him for four.
When Stevens was replaced at the Nackington Road end the pressure eased and Saif Zaib and Tom Taylor batted through the final half hour, reaching 17 and 19 not out respectively at the close.
Northants Emilio Gay said: “I think from a team perspective we couldn’t have wished for a better day batting first with the sun out. I just think we capitalised really well and built partnerships. Tomorrow morning we’ve still got some work to do, we’ve got to put out foot down and capitalise on what’s been a great day.
“When I was nearing 100, probably from 80 onwards, I was a bit more nervous than usual. In twos cricket I don’t really get that nervous but with it being my first (century) I was. Luke, with his experience just kept fist-bumping me and saying take your time, don’t get ahead of yourself and that definitely helped.”
Kent’s Tawanda Muyeye said: “The wicket wasn’t on our side really and it’s a good thing we dug deep till the end. Spirits are pretty high so hopefully tomorrow we’ll come and finish the job. I think there’s going to be some clouds tomorrow and we’ve just got the new ball so hopefully we’ll get something out of that, we’ll get our pads on and bat all day tomorrow.”