Ricketts, on loan from Leeds from the remainder of the season, collected a ball from Micah Hyde to drill the ball into the bottom left of the goal.
Burnley keeper Brian Jensen was kept busy, saving from Nick Chadwick, Paul Wotton, Elliott Ward and David Norris.
Gifton Noel-Williams was thwarted at the other end, trying from long range, as was the busy Ricketts.
Plymouth manager Tony Pulis:
"We let ourselves down in the final third. We had enough possession and opportunities but we have to start taking our chances.
"I am not disappointed with anything, the commitment or the way we played.
"The biggest disappointment was that little bit of quality we lacked in the final third to turn that possession into better chances."
Burnley: Jensen, Duff, McGreal, Sinclair, Harley, James O'Connor, Hyde, Garreth O'Connor (Elliott 72), Branch, Noel-Williams, Ricketts.
Subs Not Used: Karbassiyoon, McCann, Spicer, Courtney.
Goals: Ricketts 24.
Plymouth: Larrieu, Barness (Buzsaky 75), Doumbe, Ward, Connolly, Norris, Nalis, Wotton, Capaldi, Evans (Zebroski 76), Chadwick.
Subs Not Used: McCormick, Aljofree, Hodges.
Ref: T Kettle (Berkshire).