Hampshire conceded a first-innings deficit of 255 as Somerset amassed 474-8 declared at The Ageas Bowl today.

Ryan McLaren took 5-104, his first first-class five-for for four years and his first in the County Championship since his second season with Kent in 2008.

But James Hildreth's 167-ball 152, his third Championship hundred of the season, laid the foundation for the biggest total Hampshire have conceded at The Ageas Bowl this season. 

After beginning day two of the Specsavers County Championship match at The Ageas Bowl on 66-1 in reply to Hampshire’s 219, Somerset added 134-1 this morning, 158-3 during the second session and another 116-3 after tea, before deciding they had enough.

Marcus Trescothick (42) became McLaren’s second victim in the seventh over of day two when he edged to Sean Ervine at second slip.

But former Hampshire batsman Johann Myburgh (110) and Hildreth added 167 for the third wicket.

Myburgh, who made two fifties in six Championship matches for Hampshire in 2011, batted very fluently, hitting 17 fours from his 161 balls.

He finally went to an excellent catch by Tino Best at mid-on, attempting to hit Mason Crane over the top.

Best had received a second warning for following through down the middle of the wicket, while bowling from the Pavilion End this morning, having been similarly reprimanded yesterday.

Hildreth reached his third century of the season (125 balls) by stroking the 16th of his 24 fours soon after Tom Alsop was carried off for treatment after being struck while fielding at short-leg.

The dismissals of Jim Allenby (22) and Peter Trego (5) provided some welcome relief for Hampshire, amidst the toil.

McLaren had his third wicket when Allenby became the first of his three lbw victims, trapped by an off-cutter.

Crane was excellent during a marathon spell (21-1-96-2) and celebrated his second wicket, when Trego sent a thin edge into the hands of Ervine at first slip five overs later.

McLaren had a deserved five-wicket haul when Hildreth was pinned in front and Lewis Gregory lbw in successive overs after tea with the second new ball.

Jamie Overton soon chipped Tino Best to mid-on.

But Somerset's tenth-wicket pair smashed 82 from 64 balls before being called in.

Ryan Davies, Somerset's 19 year-old wicketkeeper, helped the visitors secure maxium batting points before thumping three sixes against a tiring Crane in his run-a-ball 39-ball 52 not out.

Crane kicked the turf in frustration after ending an expensive four-over sell (4-0-44-0) by conceding 14 in three balls.

Craig Overton launched a maximum against Gareth Berg in his 46-ball 35no as Somerset raced to their declaration.  

Faced with a tricky ten overs before the close, Hampshire lost Jimmy Adams in the second, when the left-hander chopped on against Gregory's fifth delivery.  

Hampshire bowling: Best 20-3-63-1, McLaren 23-4-104-5, Berg- 21-3-91-0, Ervine 5-0-18-0, Dawson 6-0-33-0, Crane 25-2-140-2