Kyel Reid's double earned the U's a point at Grimsby, who needed a late penalty to share the points.
Reid had put the U's ahead on two occasions, the first on four minutes and the second just before the hour mark.
Hooper equalised the first one less than two minutes after Reid's opener, but the second leveller came just two minutes before the start of injury time at the end of the game.
John McGreal made three changes to the starting eleven, bringing in Mandron, Reid and Comley, and would have asked his side to start the game well.
He got his wish, with the U's forcing a corner in the very first minute, and then they only took four to take the lead.
A second corner from Kyel Reid was hurriedly punched back out to him by keeper James McKeown, and the U’s winger moved the ball inside onto his left foot.
Once he had got himself into a shooting position on the edge of the box, Reid hit a shot straight at McKeown but it went through the home keeper’s arms and legs and into the net.
Unfortunately, the lead lasted less than two minutes – a long ball evaded Ryan Inniss and then JJ Hooper held Inniss off before volleying into the bottom corner for the quick response from Grimsby.
Inniss then gave the hosts a chance to take the lead themselves, but after his wayward pass found Woolford, the Grimsby winger hit the shot over the bar.
Reid was having plenty of set piece practice, with corners and free kicks, and from the second free kick, he forced McKeown to dive to his left to save.
That chance came on eighteen minutes and it preceeded a period where both teams struggled to find any fluidity and goalscoring opportunities were few and far between.
In fact, the nearest either side came before the final five minutes of the half was when Brandon Hanlan miscued a far post effort from a decent cross from Reid.
When the final five minutes came round, it was the hosts who were cursing their luck in front of goal.
Dembele hit the post with Sam Walker beaten, and the same player was denied by a diving Walker before the rebound was cleared.
There wasn’t such an explosive start to the second period, and it wasn’t until the fifty seventh minute that either side got a shot away.
Kent blocked the first, then Walker made a smart save from Woolford – and then two minutes later, the U’s were ahead.
A great interchange between Reid and Vincent-Young saw the former take the ball inside the defender and curl a fantastic effort into the bottom corner with the outside of his left foot.
On seventy minutes, Sean Murray and Sammie Szmodics replaced Hanlan and scorer Reid, but Szmodics didn’t last long.
He was challenged by Summerfield and had to be stretchered off five minutes later.
The U’s were comfortably holding onto their single goal lead, but that changed on eighty eight minutes, when Ryan Jackson committed a foul at the far post and sub Jamille Matt stepped up to score.
Both sides then had chances in injury time, but Wright’s volley flew just wide and Summerfield’s shot was saved.
It might have felt like a defeat for the U’s with the late equaliser, but the point ended the four match away losing run, and gave McGreal’s side something to build on with the trip to Yeovil on Saturday.