Oxford United upset the odds and Championship promotion hopefuls Newcastle to advance to the FA Cup's fifth round.
Aleksander Mitrovic forced the best opportunities of the opening 45 minutes but failed to break the deadlock as neither side created clear-cut openings.
It was the hosts who drew first blood through a Kane Hemmings finish from close range immediately after half time. Mitrovic was given the chance to pull level with a penalty but his effort was saved.
The home side then made sure of the result with Curtis Nelson heading in following a corner and Antonio Martinez nodded home a third to put the icing on the cake.