Jack Midson scored a second-half double as AFC Wimbledon piled more misery on relegated Plymouth Argyle.
Midson scored twice in six minutes - his first from 12 yards out and the former Oxford striker then converted Sammy Moore's cross.
Tom Hitchcock had the hosts' best chance but failed to control a poor clearance by keeper Seb Brown with the goal gaping.
Relegated Plymouth are still searching for their first league win this season.
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Plymouth boss Peter Reid told BBC Radio Devon:
"I think there's an anxiety in there and we've had a chat about it and it wasn't good enough.
"I know we've got a lot of young players and I've made excuses but I can't make excuses for that [display].
"You need to get your shape, you need to pull in and be resilient and we weren't."
AFC Wimbledon boss Terry Brown told BBC London:
"A big win for the club, and every win we get is greeted with relief and joy.
"I thought first half they were the better side and could have gone in at half time in front. We made some changes and got some fresh legs on and the boys played very well.
"I expect them to play better than today, hopefully we can win enough games to see by Christmas and see if we can possibly make the play-offs."