Tim Murtagh’s five-for and an unbeaten opening stand of 139 between Sam Robson and Nick Gubbins made it Middlesex’s day at Lord’s.
Having resumed on 219-2, Somerset looked on course to make a big score with former Middlesex skipper Chris Rogers not out on 104.
However, Murtagh removed Rogers (109), Jim Allenby (0) and James Hildreth (68) all within the first seven overs of the day as Middlesex hit back.
Peter Trego (65) and Lewis Gregory (49) responded with a sixth-wicket partnership of 113 to take the visitors to 346-5.
But Middlesex took the final five Somerset wickets for just 30 runs, with Murtagh bowling Trego and Ollie Rayner having Gregory caught at the wicket.
Robson, discarded by England two years ago, continued in his rich vein of form, having scored 451 runs in his previous three innings at Lord’s this season.
He hit 10 fours in his 67 not out, having been dropped twice in the 50s, while Gubbins kept a similar pace to ensure Somerset could not make any inroads before stumps.
This post was last modified on 24/05/2016