|LV= County Championship Division One, Taunton|
|Close, day two: Lancashire 266 v Somerset 193-2|
|Somerset 3pts, Lancashire 2pts|
Marcus Trescothick struck an unbeaten 107 to lead Somerset's reply against Lancashire on day two at Taunton.
Trescothick, whose 248-ball innings included 15 fours and one six, shared 144 with Alviro Petersen (57 not out) to leave the hosts 193-2 at the close.
Lancashire had begun the day on 221-6, but lost their last four wickets for the addition of just 45 runs.
Kyle Hogg and Simon Kerrigan both fell to George Dockrell (3-48) to leave Glen Chapple stranded on 27 not out.
Dockrell, Alfonso Thomas (3-34) and Lewis Gregory (3-65) were the mainstays of Somerset's attack as Lancashire were restricted to only 266 after winning the toss and choosing to bat.
But the second day belonged to former England opener Trescothick, who scored his third County Championship century of the summer after taking 31 deliveries just to get off the mark and was then dropped by Ashwell Prince on 25.
In compiling the 54th first-class ton of his career, he also become the highest-ever scorer at Taunton, his 7,333 runs taking him past Lionel Palairet.
Somerset director of cricket Dave Nosworthy:
"Marcus Trescothick's century was right up there with the best innings I have seen in my coaching career because it was tough to bat on that pitch and it needed the right mentality from the start.
"Alviro Petersen also played well and we need both of them to push on tomorrow because we are by no means in control of the game at this point."
BBC Somerset's Anthony Gibson:
"This was Somerset's day and, above all, Marcus Trescothick's day as he showed patience, judgement and huge determination in scoring his third century of the season.
"It was slow going for the first 50 overs of Somerset's reply, on a painfully slow pitch, but once Alviro Petersen joined his captain, the batsmen gradually got the upper hand, as Lancashire's bowlers tired in the sunshine.
"By close of play, they had added an unbeaten 144 together, and taken Somerset to a position of strength, if not quite yet of ascendancy."
BBC Radio Lancashire's Scott Read:
"Lancashire stuck at it really well on a long hot day in the field, bowling on a slow pitch that looks difficult to score quickly on and might only get slower.
"Somerset just about managed to go at around two runs an over, a reflection of the pitch and accuracy of the Lancashire bowlers.
"With the new ball due first thing in the morning Lancashire will be hoping for early wickets, else they could be facing a sizeable deficit."