And with Tomlinson and Cork bowling well, they looked set for a miserable day as NeilEdwards, Alex Hales, Samit Patel and Bilal Shafayat all went cheaply.
Openers Marcus Trescothick and NeilEdwards threw away their wickets in similar style, pulling catches to David Wainwright at deep square off short-pitched balls from Bresnan.
It was 145-six when Arafat was well caught by substitute fielder NeilEdwards at second slip but two more short breaks for rain held up Somerset's victory push.