Somerset edged ahead on a curtailed day three of their County Championship Division One game with Durham at Chester-le-Street.
The home side began the day 92-8 in their second innings before swiftly succumbing to finish on 116.
An unbeaten 39 from Craig Kieswetter in their reply helped Somerset to 96-2 at stumps, after bad light meant only 35 overs of play were possible.
Phil Mustard was 23 not out overnight but he was run out after adding just two more runs, Jamie Overton's excellent throw doing for him after he had turned Alfonso Thomas to fine leg.
Thomas (4-29) then wrapped up the innings when Chris Rushworth edged through to wicketkeeper Kieswetter, who claimed his fifth catch of the innings and his eighth of the match.
Somerset began their victory pursuit positively enough as they scored 30 runs off the first six overs, including 10 off Rushworth's third.
Arul Suppiah took control but he was trapped leg before for 17 by Graham Onions.
A 20-minute break for bad light soon followed before Kieswetter went on to dominate a stand of 43 with Marcus Trescothick, the keeper hitting two of his five boundaries off successive balls from Onions.
Trescothick looked less assured as he was twice beaten by Callum Thorp, who went for just 10 runs in nine overs.
Somerset captain Trescothick looked to have weathered the storm only for Ben Stokes to pounce after replacing Onions.
Trescothick (22) played back to his fifth delivery and got an inside edge into his stumps.
James Hildreth was unbeaten on 12 alongside Kieswetter when the gloom closed in again, to leave Somerset requiring 138 runs for victory on what is expected to be a more pleasant final day in the north east.