Batsman Usman Khawaja made Glamorgan history by becoming the first player ever to score centuries in his first three games for the county despite Northamptonshire taking control on day two in Cardiff.
Khawaja made 103 in a total of 254 as Glamorgan whittled Northamptonshire's lead to just 27, however by the close the away side had raced to 169/0.
"It's always nice to score runs, I've been enjoying my cricket since I've been here in Cardiff and Glamorgan, so hopefully that'll keep happening but it would have been nicer with a few wickets," said Khawaja.
"There were a few ifs and buts whether I could get here in time (to play Championship matches) because I was waiting for a visa in India, I got here with not much time to spare before my first game, got that first hundred and it's nice it's flowed on from there and I'm having fun in the middle.
"I found it the toughest pitch we've played on yet, but their guys batted really well and made it look easy. It's a long way back so we're going to have to bowl well in the morning."