Kyle Edwards and Ruben Rodrigues inspired Oxford to a 3-0 win over promotion rivals Exeter in front of more than 10,000 fans at the Kassam Stadium.
Oxford went ahead in the eighth minute when Edwards, on loan from Ipswich, delivered a measured cross from the left for Rodrigues to head in his first goal for the club from six yards.
The Grecians had chances to level, with Reece Cole twice having shots saved, before Cameron Brannagan sealed United’s victory with two late penalties.
Will Aimson tripped Rodrigues seven minutes from time and Brannagan hit his first penalty low into the bottom left corner.
Substitute Josh Murphy was then brought down by Will Aimson in stoppage time and Brannagan converted his second spot-kick in almost identical fashion.
Edwards proved a thorn in Exeter’s side throughout the first half and twice set up opportunities for Billy Bodin.
From the second of them goalkeeper Viljami Sinisalo did well to turn Bodin’s powerful drive around a post.
The Grecians, who had been looking to make it three wins in a row away from home in League One, threatened with Tom Carroll heading Demetri Mitchell’s cross wide at the near post.
Harry Kite sliced a 20-yard effort wide and former Oxford forward Yanic Wildschut saw a fierce angled shot come back off a post.
Oxford left-back Ciaron Brown hammered a long range left-footed drive wide early in the second half and Brannagan went close with a shot that Sinisalo appeared to touch on to a post.
Cole saw his 25 yard free-kick beaten out by home keeper James Beadle, who saved again from Cole on his knees moments later, before Brannagan’s pair of penalties killed off Exeter.