Keaton Jennings received notable help from England Under-19 batsman Jack Burnham as Durham reached 98-2 after being put in by Somerset at Emirates Riverside.
There was no need for a toss under the new rule allowing visitors to field first, but Somerset's new captain, Chris Rogers, would have hoped for further inroads.
Although the ball swung on a sunny morning, left-hander Jennings stood firm to reach 39, with Burnham on 17, at the interval.
He was preferred to Gordon Muchall, while 20-year-old South African paceman Brydon Carse was handed his championship debut, and Somerset included Scottish seamer Josh Davey.
Durham had 30 on the board by the seventh over, but a switch of ends for Lewis Gregory brought swift rewards.
He was replaced at the Finchale End by Tim Groenewald, who found the shoulder of Mark Stoneman's bat when the left-hander was shaping to turn him to mid-wicket, the ball flying to Tom Abell at point.
An over from Jim Allenby cost 12, but he was on merely to allow the switch and Gregory struck with his second ball from the Lumley End. It skidded on to have Scott Borthwick lbw for 14, bringing in Burnham at 55-2.
He was swiftly underway, but showed excellent judgement in what to leave before striking two fours through the offside just before lunch.