The 15-point away win was sufficient to earn Plymouth the four match points they needed to overhaul Ipswich and finish in the top six.
The Devils will now meet third-placed Glasgow in the play-off quarter-finals with the winners due to meet runners-up Somerset in the semi-finals.
Morten Risager led the way for Plymouth with three wins in his 13-point return and there were also double figure scores from reserve Linus Eklof on 12 (paid 14) and Jack Holder with ten (paid 13).
Skipper Kyle Newman had to withdraw from the meeting, suffering from dizziness after a fall in his third outing.
Rye House: Edward Kennett 15 (5 rides), rider replacement for Luke Bowen, Kasper Lykke 5+1 (6), Robert Lambert 11 (4), Nikolaj Jakobsen 3 (2). Reserves: Danny Maassen 1 (5), Ben Morley 3 (6), Danny Ayres (No 8) 0 (2).
Plymouth: Ryan Fisher 6+3 (5), Morten Risager 13 (6), Jack Holder 10+3 (5), rider replacement for Todd Kurtz, Kyle Newman 4 (2). Reserves: Sam Simota 8+2 (6), Linus Eklof 12+2 (6)