Somerset 185 for 8 (Trescothick 52, Finn 4-41) trail Middlesex 283 by 98 runs
Scorecard
Steven Finn took 4 for 41 to spearhead a second-day Middlesex thrust with the ball as Somerset slipped to 185 for 8 in their Championship Division One match at Merchant Taylors' School in Northwood.
Marcus Trescothick and Tom Abell had put on a battling 76 for the first wicket in reply to Middlesex's 283, but Finn took two of four wickets to fall for 41 runs as Somerset suddenly found themselves struggling at 117 for 4. Peter Trego was then leg-before to Ollie Rayner for 15, just before heavy rain arrived to drive the players from the field at 3.33pm for an early tea.
Jim Allenby, hit under the throat by a short ball from Toby Roland-Jones when 28, fought hard to score 43 before becoming Finn's fourth victim as he edged low to Rayner at second slip.
Finn is due to be replaced in this match by James Harris when he joins up with England's squad ahead of the second Ashes Test, but he clearly wanted to make a mark before his departure. His third wicket was that of Lewis Gregory, caught at the wicket for 11 soon after a restart at 5.05pm, and he also had Michael Bates dropped on nought by James Franklin at first slip.
There was another break of half an hour from 5.37pm as more rain arrived and only 20 minutes of further play was possible before bad light brought a close to proceedings with Middlesex firmly on top despite the loss of 25.3 overs in the day.
Running down the slope from the Benham End, Finn first forced Abell to feather a catch behind on 26 and, after Tim Murtagh had induced a thick edge to the keeper by Johann Myburgh, on 1, the England fast bowler produced another beauty to bowl James Hildreth for 4.
Trescothick's determined three-hour 52, from 124 balls, was finally ended by Roland-Jones, who swung one into the left-hander's pads to have him leg-before.
Finn had been a handful for Somerset's openers in the morning session, striking both Trescothick and Abell on the arm and hand respectively during a fierce new ball spell. Somerset had started their reply this morning, after taking the final Middlesex first innings wicket in the closing overs last night, and Finn hit Abell early on and Trescothick when he was on 16.
The cricket was so attritional that Abell's first boundary did not come until the last over of the morning session, the 29th, when he cut off spinner Rayner's first ball to the third man ropes. It was the 77th ball he had faced.