Tim Bresnan took the only Lancashire wicket to fall during the third morning of the three-day friendly at Headingley.
The Yorkshire all-rounder had Stephen Moore caught low down at fourth slip by Liam Plunkett during a six-over spell which cost him 12 runs as the Red Rose county reached lunch at 105-1 from 31 overs of their second innings.
Tom Smith posted a 79-ball half-century with nine fours, two of which came via inside edges past the keeper and two more driven arrow straight down the ground. He later hit Adil Rashid over long-on for six.
Yorkshire had declared their first innings overnight on 381-8 in reply to 269-7 declared.
Lancashire are now expected to declare their second innings midway through the afternoon session, no matter how many runs they are ahead.
Smith had reached the break on 65 not out, with Karl Brown unbeaten on 18.