It wasn’t quite fireworks at Grenoble Road on Bonfire Night, but that will matter little to United, who sealed an important three points against Hull City.
The only goal of the game came 10 minutes into the second period, when ter Avest was in the right place at the right time, to meet a left wing cross and stab the ball home from close range.
Des Buckingham made five changes to the side which lost to Swansea City, with Peter Kioso, Ruben Rodrigues, Louie Sibley, Owen Dale and Mark Harris all dropping out of the starting XI.
Dutch right back ter Avest, plus Greg Leigh, Will Vaulks, Idris El Mizouni and Dane Scarlett were the players who came into the side, which also saw a change of shape.
The U’s lined up in a 3-4-2-1 formation which saw Leigh and ter Avest provide the width from wing back, while Tyler Goodrham and El Mizouni tucked in as two No 10s behind Scarlett.
It was predominantly all the Tigers in the first half though, with Kasey Palmer hitting an early right-footed effort off target following a Mohamed Belloumi cross.
Right winger Belloumi then picked out the late run of Xavier Simons on the edge of the penalty area, but the latter fired high and wide.
A clever move from the visitors then saw Abdulkadir Omur get through against Jamie Cumming, however the goalkeeper made an excellent save with his feet to protect his near post.
Another chance was provided to the dangerous Belloumi when Leigh failed to clear the ball effectively inside the box, providing Belloumi with a shooting opportunity, but he arced his shot over.
Belloumi was then allowed to drift infield from the right-hand side, and he smacked the far post with a left-footed strike from the edge of the area.
United had their first attempt with just a minute to go until the break, when a great cross from Leigh picked out ter Avest, whose header forced a save out of Ivor Pandur.
El Mizouni and Scarlett then got in the way of each other as both players went for a bicycle kick from the loose ball.
The half ended with a smart short corner routine reaching Lewie Coyle, who saw a shot deflect over for a corner which came to nothing.
The Tigers began the second period where they left off the first, as a cross from skipper Coyle found Simons, who fired off target with a volley on the edge of the area.
The U’s took the lead though 10 minutes into the second half. The move began with a glorious switch of play from Goodrham out to Leigh on the opposite flank, and the latter’s dangerous cross made its way to ter Avest, who took a touch and then stabbed the ball past Pandur in the Tigers goal.
Just after the hour mark though, Buckingham was dealt yet another injury blow as Ben Nelson was forced off with looked like either a shoulder or arm injury, with Sam Long coming on in his place.
While ter Avest showed his worth at one end, he also demonstrated his defensive nous at the other when he stepped in the way of Palmer just as the Hull attacker looked set to pull the trigger from the centre of the box.
Buckingham made a double switch with just under 20 minutes to go, as Kioso and Harris replaced ter Avest and Scarlett respectively, while Rodrigues came on for El Mizouni in the closing 10 minutes.
There were a few hearts in mouths when a cross from the right narrowly evaded the back post after a touch from Joao Pedro in the box shortly before eight minutes of stoppage time were added on.
United stood firm though and kept the visitors out in an organised and professional manner.
Oxford United (3-4-2-1): Cumming; Nelson (Long 62), Moore, Brown; ter Avest (Kioso 71), Vaulks, McEachran, Leigh; Goodrham, El Mizouni (Rodrigues 80); Scarlett (Harris 71).
Unused subs: Ingram, Dale, Ebiowei, Ferdinan, Goodwin.
Booked: Brown.
Hull City (4-2-3-1): Pandur; Coyle, Jones, Hughes, Giles (Drameh 69); Slater, Simons (Puerta 78); Belloumi (Burstow 78), Palmer (Bedia 84), Omur (Jarvis 69); Joao Pedro.
Unused subs: Racioppi, McLoughlin, Burns.
Booked: Hughes.
Referee: Will Finnie (Bedfordshire)
Attendance: 10,213 (TBC visitors)