Steven Croft scored an unbeaten century as Lancashire dominated Somerset with the bat on the opening day at Taunton.
Croft (113 not out), who hit 11 fours and two sixes in his fifth first-class hundred, shared a 208-run fourth-wicket partnership with Ashwell Prince (96).
But Prince became a maiden first-class victim for 18-year-old Craig Overton.
Karl Brown (50) and Stephen Moore (47) also contributed, while Lewis Gregory, Vernon Philander and Peter Trego also picked up a wicket each for Somerset.
After electing to bat, Lancashire lost a wicket to the fifth ball of the day as Paul Horton was trapped lbw to South Africa Test star Philander with only two runs on the board.
But a Somerset attack lacking Steve Kirby, Adam Dibble and Gemaal Hussain through injury, and Alfonso Thomas, who is playing in the Indian Premier League, was soon exposed.
And despite a few moments, it was very much Lancashire’s day.