Michael Appleton's first match in charge of Oxford ended in a 1-0 defeat to Burton at the Kassam Stadium as summer capture Lucas Akins scored on his debut for the Brewers.
Akins, 25, who joined from Stevenage, pounced from eight yards in the 42nd minute after Stuart Beavon's powerful run past two defenders on the left carved open Oxford's defence.
Both sides had five players making their debuts with Appleton giving the nod up front to England Under-19 striker Carlton Morris, on loan from Norwich, ahead of Danny Hylton, signed in the summer by previous boss Gary Waddock.
The U's began brightly, with Josh Ruffels having a fierce drive parried after good interplay between Alfie Potter and the 18-year-old Morris.
Dominic Knowles squandered a good chance for Burton when he mis-kicked from eight yards out, and Beavon twice forced saves from George Long.
Potter went close again for Oxford when he met Joe Riley's right-wing cross with a firm header that Jon McLaughlin just managed to beat away.
Burton controlled most of the second period, playing in Oxford's half as the game disappointingly petered out for the home team.