Both sets of players entered the field to a party atmosphere at the Kassam, balloons thrown into the air with the three stands bathed in glorious early May sunshine.
Oxford, who won 5-0 when the sides met in the league last month, attacked the game with an intensity that matched the atmosphere, raining shots on Jed Steer’s goal but were unable to find the back of the net.
Josh Murphy was a constant threat down the left-hand side for Des Buckingham’s side, causing Jadel Katongo all sorts of issues and often beating his man to force a cross into the box or shot on goal.
Peterborough boss Darren Ferguson noticed the need for change at the break, introducing Kwame Poku, who fired narrowly over the bar just minutes after his substitution.
It was the Yellows who took the lead, though, when Josh Murphy’s deep corner found Cameron Brannagan, who looped a header high to the back post where Moore was waiting to score his second of the season.
The visitors reacted well to going behind, growing in confidence and forcing Oxford deeper and deeper into their own box as the clock ran down.
Ricky-Jade Jones was given a glorious chance to level but completely misjudged Poku’s delivery, the ball deflecting off him for a goal kick.
Despite their late pressure, the Posh – who won their first leg of their play-off semi-final with Sheffield Wednesday last season 4-0 only to eventually lose on penalties – were unable to find an equaliser, leaving Oxford with a slender advantage to take to Cambridgeshire.
