TEST batsmen Keaton Jennings and Stephen Cook staged an unbroken half century stand to defy Gloucestershire's new ball bowlers on the second day of the Specsavers County Championship Division Two match at Bristol.

Replying to the home side's first-innings 303, Durham's opening pair reached 53 without loss by lunch to lay solid foundations.

Experienced South African campaigner Cook (26 not out) and young England left-hander Jennings (26 not out) proved ruthless in their exploitation of anything short of a length, accruing six boundaries between them to put Gloucestershire's performance with the bat into perspective.

Gloucestershire resumed their first innings on 265-7 and Durham's seamers made good use of the new ball to mop up the last three wickets for 38 runs in 15.2 overs, Chris Rushworth finishing with 3-55. A stand of 36 for the eighth wicket between Jack Taylor, who fell three short of a second successive 50, and David Payne banked the home side a third batting bonus point.

Taylor, Payne and Chris Liddle all succumbed to defensive edges as the England triumvirate of Rushworth, Mark Wood and Graham Onions took care of business.