COUNTY CHAMPIONSHIP DIVISION ONE, Taunton
Somerset v Durham
28 April - 1 May (Play starts 1100 BST)
CLOSE OF PLAY, DAY TWO: Durham 543, Somerset 69 and 83-1
(Somerset 3 pts, Durham 8 pts)
Graham Onions celebrated his England call with a six-wicket haul as champions Durham steamrollered Somerset into submission at Taunton.
Onions took 6-31 as Somerset were bowled out for just 69 in reply to Durham's massive 543, engineered by Dale Benkenstein's county-best 181.
Justin Langer made over half his team's score, unbeaten on 35.
Somerset followed on 474 runs behind but have so far made a better fist of it second time round, closing on 83-1.
But it was Onions' day as, after taking eight wickets in his previous Championship match against Michael Vaughan and Yorkshire last week, he further justified his England selection.
The Durham paceman took his six wickets in just 14.2 overs to sound a warning to the West Indies with a devastating spell of accurate seam bowling.
Dale Benkenstein had earlier been last man out for 181, his best-ever Championship score, as Durham added 171 more to their overnight 372-6.
Benkenstein was unbeaten on 110 overnight and, while tied down for a while early on, rarely looked in any trouble as he progressed to 150 off 254 balls, with 20 fours.
After Phil Mustard had been run out cheaply by a fine piece of fielding by Peter Trego, Callum Thorp (32) and Mitchell Claydon (38) helped take Durham not only to maximum batting points, but also to a score that looked way above par on a green pitch.
And Onions was soon exploiting the wicket in a way none of Somerset's wayward seamers had been able to do.
He beat Trescothick for pace, bowling the former England opener for 12 in the second over. Then he struck twice in the same over as he caught and bowled Arul Suppiah off a leading edge for 12 and pinned James Hildreth lbw playing no shot for a duck.
Steve Harmison had Zander de Bruyn caught behind down the leg side without scoring and two more ducks followed as Onions had Craig Kieswetter taken in the slips and Peter Trego caught behind off an attempted pull shot.
Trego looked unlucky as the ball seemed to strike his upper arm. But only skipper Langer showed any resistance as Somerset's tail folded tamely, Onions removing last man Charl Willoughby to claim his sixth victim.
It had been a performance full of vigour by 26-year-old Onions, who bowled 12 overs in his opening spell before tea from the River End, taking 5-30.
Second time around, Somerset progressed to 49 before Suppiah was given out lbw pushing forward to Claydon. But Trescothick looked in ominous touch as he and Hildreth saw the home side to the close, still needing a daunting 391 to make Durham bat again.