In a friendly arranged to provide Campbell and Peter MacDonald with match sharpness ahead of Wednesday's Boxing Day meeting with Partick Thistle, the 11-goal frontman opened the scoring.
After an early reshuffle in which Ton went from 3-5-2 to 4-4-2, Kyle Wilkie dissected the Lok defence with a precise angled pass for Declan McDaid, who unselfishly squared for Campbell to tap in.
Pollok substitute Willie Sawyers raced on to former Morton man Carlo Monti's pass to round David Hutton and roll in the equaliser on 63 minutes.
The hosts took the lead four minutes later when Paul McQuilken's 22-yard free-kick crept past Ton keeper Hutton and into the bottom-right corner with the aid of a deflection.
But Aidan Ferris, a 16-year-old striker who has been catching the eye in the Cappielow club's youth academy, turned home an 86th-minute leveller to secure a draw.
Morton (3-5-2): Hutton (7); Jamieson (5) (Irvine 70, 5), Naismith (7), O'Ware (6); McDaid (6) (Russell 43, 6), Wallace (7), Keogh (6) (Nicolson 79, 4), Wilkie (7) (Lynch 55, 4), Halsman (5); MacDonald (6) (Ferris 70, 6), Campbell (6) (Hawke 65, 4).