Williams, slight favourite before the match, gained a 6-3 advantage in the first session over his rival from Carmarthen and was more than halfway to his target of 10 frames.
Stevens made an encouraging start, taking the opening two frames and including a break of 81 to lead 2-0. Williams dominated the next two as Stevens scored just 20 points to draw level by the first interval.
When Stevens missed a green early in frame five, Williams pounced with his second half-century to take the lead for the first time. Helped by a couple of flukes he doubled his advantage, and the luck held for the next two frames.
Stevens should have reduced his arrears to 4-3 but missed a straightforward pink, trying to hold position for the black. At 5-2, Williams fluked the last red out of a snooker enabling him to go 6-2 in front.
But Ste.vens, who broke his major tournament duck at the Regal Masters last September, gamely made 60 to finish the session three frames down.
Scores, Digest, page 9Reuse content