Peter Trego hit a rearguard 86 to revive Somerset as Notts closed 206 behind at 46-2 after two days of the top of the table match at Trent Bridge.

Trego hit 11 fours in a season's best innings, sharing 90 for the ninth wicket with Andy Caddick, who made 35.

It helped Somerset progress from 143-7 to 252 and earned two batting points.

Bilal Shafayat was dropped at gully in the Notts reply, but Will Jefferson edged behind and nightwatchman Andre Adams drove to gully four balls later.

Trego was only on 17 overnight and soon lost Alfonso Thomas in the second full over.

It prompted Trego to go on the attack, and he was soon unsettling the Notts attack with a series of pulls and upper cuts.

In sight of his first hundred since a 113 against the same opposition at the end of last season, Trego was caught on the run by mark wagh at deep mid-wicket when England spinner Graeme Swann was brought on.

Swann, who missed the first day having been with the England squad for the final one-day match in Cardiff, also ousted Charl Willoughby to leave the home openers with two overs to face before lunch.

Rain prevented the innings from resuming until 1700 BST and Shafayat survived both an appeal for a low catch at cover and a dropped catch by Wes Durston.

The two wickets before stumps gave Somerset the ascendancy at the halfway point.