Earlier Lancashire’s bowling discipline stood in contrast to some loose strokeplay from home batters, Ricardo Vasconcelos (39) the only top-order batter to prosper.
Will Williams (2-39) struck in the day’s second over, the ball flying off the splice of Luke Procter’s bat to gully.
George Bartlett and James Sales took the score to 33 when Bartlett was adjudged caught at third slip off George Balderson. Sales then cracked Phillip through extra cover for four, but the West Indian squared him up next ball as he edged low to Jennings at second slip.
Rob Keogh was next to go, pushing outside off-stump, caught low down by Marcus Harris at third slip.
Vasconcelos meanwhile was finding runs all around the wicket, hitting six over square-leg, driving and pulling comfortably before Phillip jagged one back to trap him lbw.
Three balls later Saif Zaib had a rush of blood, charging down the pitch to Balderson, edging to Jennings at second slip to leave Northamptonshire reeling.
Harrison (29) and McManus showed greater application ensuring no further wickets fell before lunch and extended their seventh-wicket partnership after the interval to 60.
Lancashire shelled two catches in quick succession, with Harrison and McManus both benefiting but Phillip returned to the attack to quickly break the partnership, nipping one back to take Harrison’s inside edge, wicketkeeper Hurst taking the catch.
Ben Sanderson had some fun in a quickfire stand of 32 off 20 deliveries with McManus, driving square for four and edging over the slips for another boundary. He punched Willliams through cover before the bowler snared him lbw.
McManus was in excellent touch and he added 57 in 10 overs with Guthrie before falling in low-key fashion, caught off the leading edge off Bailey, the ball ballooning up to Luke Wells running from mid-off.
Guthrie smashed Balderson through midwicket and pulled a no-ball for another boundary, but departed when he hit the all-rounder straight to mid-on.
