The Devils are now five points behind sixth-placed Ipswich with three matches in hand.
Ipswich were looking to take at least a losing bonus point from the meeting and restricted Plymouth to a five-point lead after eight heats, but the Devils finished strongly with three maximum 5-1 heat wins in the final seven races.
Plymouth provided 10 of the 15 race winners with Ipswich relying heavily on Danny King, who had four of their five wins and scored 16 points. In contrast Plymouth scored consistently throughout their team.
Co-promoter Ashley Taylor said: “Because of the league position of the two teams it was a big meeting for both sides. After the last two weekends with victories over Edinburgh and Somerset we are now in a position as serious play-off contenders.
“Ipswich came here looking for at least a point, and this result could be crucial come the end of the season.”
Plymouth: Kyle Newman 9 (4 rides), James Wright 2+1 (3), Jack Holder 9+2 (5), Morten Risager 9 (5), Ryan Fisher 8+1 (4). Reserves: Sam Simota 6+1 (4), Todd Kurtz 11+1 (5).
Ipswich: Danny King 16 (5), rider replacement for Rohan Tungate, Gino Manzares 4+1 (4), Cameron Heeps 6 (5), Aaron Summers 8+1 (6). Reserves: Stefan Nielsen 1 (4), Ashley Morris 4 (6).