Woodman again denied Elliott with a great reflex save 5 minutes into the second half.
It wasn't until the 58th minute that the first goal went in, with Elliott the instigator. He went on a surging run through the middle and after beating two men, played it to Ben Burgess. He curled in a left-foot shot from the right side of the area to make it 1-0.
5 minutes later, City doubled their lead. Elliott again assisted, passing to Allsopp whose shot went over Woodman under the challenge from a defender.
The goal blitz continued, and in the 66th minute Allsopp was on target again. Burgess passed and the Tigers number 10 finished from the left-side to make it 3-0.
City had opened up the visitors, and Allsopp had another chance a minute later but Woodman smothered it at his feet. Elliott then rose to head a corner goalwards but saw it blocked on the line.
Oxford pulled one back with 15 minutes to go from a corner. Andy Dawson blocked the shot on the line but Steve Basham blasted home the rebound.
But City's three-goal lead was restored in the 79th minute. Stuart Green's near-post corner was hit towards Burgess under pressure from two defenders, and who's head nodded it in was unclear, but City were 4-1 in front all-the-same.
The away side managed a consolation in injury time to reduce the deficit. Damien Delaney gave away a free kick on the edge of the area, and from a lay-off Matthew Bound - once a Tigers loanee - smashed it past Myhill.
But the 4-2 win was still comfortable for City who go a point clear at the top of the table. Doncaster's 2-0 win at Southend sees them go second, while Oxford are now 3 points behind leaders City, who have played a game more than the challengers.
City line-up (4-4-2): Myhill; Hinds, Joseph, Delaney, Dawson; Price, Ashbee, Green (Whittle 81), Elliott (Forrester 89); Allsopp (Holt 83), Burgess.
Un-used subs: Musselwhite, France.