The full-back latched onto a loose-ball and kicked through before beating Nick Abendanon to the touchdown eight minutes from time to boost Sale's chances of qualifying for the Heineken Cup at Edgeley Park.
Sale, who are now two points ahead of Gloucester in sixth place before Saturday's fixtures, were leading 6-3 at the interval courtesy of Nick Macleod's two penalties to Olly Barkley's one.
Barkley, who last appeared for England in the 2005 RBS 6 Nations, levelled the scores after the two kickers had traded three-pointers in the second period, before 22-year-old Miller, in his 19th start this campaign, went over the whitewash with Macleod adding the extras.
Miller has been capped at England Under-16s, Under-18s and Under-20s level, notching up 47 points in 13 appearances in the latter as well as helping the Under-20s claim the Grand Slam in 2008.
Sale chief executive Steve Diamond admitted he was delighted with the win, believing his side can still squeeze into the top four.
"We've worked hard since Saracens and we were unlucky to lose the game against Newcastle Falcons away," he said.
"We've done a lot on our defence and it showed in the last 15 minutes that they've been listening to what we've been doing in training.
"At this end of the season, if we can scrape into Europe, then they're the four points that might help us get there."
Elsewhere today, Leicester and Northampton square in a third versus fourth clash, Saracens travel to London Irish to apply pressure on league leaders Harlequins, who can secure a play-off position today at home to London Wasps.