LV COUNTY CHAMPIONSHIP DIVISION ONE, Taunton:
CLOSE OF PLAY, DAY ONE: Yorkshire 296-4
Somerset 1pt, Yorks 2pts
Lyth hits through the off side as Somerset wicketkeeper Jos Buttler looks on
Adam Lyth hit his first Championship hundred of the season to give Yorkshire the upper hand against Somerset.
He struck 15 fours in a career-best 142 and shared stands of 115 with opening partner Joe Sayers (50) and 136 with Anthony McGrath (73 not out).
But the Tykes lost three wickets for 35 runs at Taunton after Lyth was caught by Ben Phillips off Zander de Bruyn.
Phillips (3-52) then struck twice late in the day to give Somerset some solace, Yorkshire closing on 296-4.
Lyth and Sayers posted exactly 100 in the morning session after Yorkshire captain Jacques Rudolph, standing in while Andrew Gale is on England Lions duty, won the toss.
Phillips made the breakthrough early in the afternoon session when Sayers edged to second slip, but more misery was to follow for Somerset in the shape of the Lyth-McGrath second-wicket stand.
Lyth brought up his century off 163 balls, but both he had McGrath were dropped just after tea, by wicketkeeper Jos Buttler and first slip Marcus Trescothick respectively, with Phillips the bowler on both occasions.
Left-hander Lyth eventually fell when he pulled de Bruyn to mid-on before Rudolph and the inexperienced Gary Ballance both became victims of Phillips and the second new ball.
The late wickets took the shine of Yorkshire's day, but with McGrath still at the crease they remain in a strong position.
Indian spinner Murali Kartik, on his first day as Somerset's overseas player, bowled 26 overs without picking up a wicket.