The Cherries had won just one league game before they met with Michael Carrick's men, but put United to the sword with an exceptional performance.
Goals came from Rayan, Marcus Tavernier and Evanilson - yet it was defender James Hill who put in the most impressive showing.
The Englishman was a rock at the back and didn't allow Manchester United's attacking players any chance to get into the game.
Hill put up some brilliant defensive numbers with nine duels won, seven clearances, six tackles, four blocks and four interceptions - taking his overall Flashscore rating to 9.3, the highest of any player in the Premier League's latest round of fixtures.
Bournemouth are next in league action against Leeds on Saturday, October 31st.