Durham 98 for 2 trail Somerset 299 (Myburgh 118, Hildreth 53, Collingwood 5-57) by 201 runs
Scorecard
Paul Collingwood induced a dramatic Somerset batting collapse at Taunton with only the second five-wicket haul of his career.
Johann Myburgh's first Championship century for Somerset and solid contributions from Tom Cooper and James Hildreth looked to have put them in control at 224 for 2.
But Collingwood, 38, then took four wickets in 20 balls with his medium-paced seamers just before tea and added another after the break to finish with 5 for 57 as Somerset crashed to 299 all out. Graham Onions claimed 4 for 59.
Collingwood expressed mystification at Somerset's batting collapse. He said: "I'm as surprised as anyone to be standing here talking about taking five wickets on the opening day of the season.
"It was only my second five-for in first class cricket and my first for a decade. There were some good balls and some poor shots."
By the close Durham had replied with 98 for 2 from 19 overs, battling back after Lewis Gregory claimed two early wickets. Scott Borthwick cracked 12 fours in racing to a 46-ball half-century.
Myburgh went on to a 91-ball half-century and needed only 43 more deliveries to bring up his hundred, completed with a sweep for two off a Borthwick full toss.
The 34-year-old South African produced some quality cover drives and back-foot shots. He lost partner Cooper, who impressed on his Somerset debut, when he fell leg-before to Paul Coughlin, having struck nine boundaries.
Myburgh and Hildreth started to cut loose in a stand of 101, which saw the latter reach a typically attractive 65-ball half-century, with eight fours and two sixes.
Their partnership ended when Myburgh, having hit 15 fours and a six in reaching 118, directed a back-foot shot off Collingwood straight to Michael Richardson at short cover. It proved the turning point in the day.
The veteran Durham skipper, operating from the River End, quickly pinned Hildreth lbw, bowled Alex Barrow defending, and had Peter Trego leg-before as Somerset plunged to 249 for six at tea. Jim Allenby, on Somerset debut, also fell to Collingwood before Onions cleaned things up.