Jordan Clark gave the Hatters a 10th minute lead, with that doubled by Tom Krauss eight minutes before the break.
Tyler Goodrham’s lovely first-time volley brought the U’s back to within a goal shortly before half-time, and nine minutes into the second period, Ruben Rodrigues levelled the match with a neat finish.
The home side played the final 13 minutes with 10 men after substitute Liam Walsh was shown a straight red card for a reckless challenge on Siriki Dembele.
Des Buckingham made just the one change to the side which battled to a goalless draw at home to Burnley, as Owen Dale made his first league start of the campaign, in place of Dembele.
The Kenilworth Road surface faced at least three pitch inspections by the match officials in the couple of hours before kick-off, and just after 7pm, the game was given the all-clear.
It was the hosts who made an electric start to the first half, peppering shots on Jamie Cumming’s goal.
With seven minutes on the clock, Clark bought himself space just inside the penalty area and fizzed a strike narrowly wide.
Straight at the other end though, Goodrham nicked the ball down the left and played a low ball across for opposite winger Dale, however Teden Mengi did superbly well to get across and clear the danger.
With 10 minutes played, the Hatters took the lead when Rodrigues pondered on the ball for a moment too long, and had it pinched from him, allowing Clark to finish with aplomb past Cumming.
The U’s looked for an immediate leveller, and were close when an Idris El Mizouni strike was pawed away by Thomas Kaminski, before Rodrigues saw an effort from the loose ball swept away for a corner.
Left wing back Alfie Doughty then sent in a dangerous cross towards the top of the far post, and the effort had Cumming on alert, but the ball drifted just off target.
A Rodrigues strike from 25 yards was tipped over by Kaminski, while Jacob Brown’s strike from the left channel was easily held by Cumming.
Clark then volleyed wide first-time from a Doughty cross, before El Mizouni bent an effort wide from the edge of the penalty box.
Peter Kioso sent an effort from distance flying over the crossbar, while Rodrigues was again caught in possession, leading to a Hatters chance.
This time, he had the ball stolen from him close to the centre circle, and a pass was played through to Elijah Adebayo, who shot across goal and wide of the far post.
The Hatters doubled their advantage from another sloppy moment at the back from the U’s though.
A ball through into the box caused confusion between Cumming and Elliott Moore, with neither player gaining possession, and instead it was Brown who was able to lure Cumming further from his goal into the left channel and he then squared for Krauss who fired into the goal, which was being guarded by the retreating Moore.
As four minutes of stoppage time were signalled though, United clawed themselves back to within one goal when Goodrham sent an excellent first-time volley looping over Kaminski and into the goalkeeper’s far post.
Buckingham made a switch at the break, as Kyle Edwards was introduced for Dale on the right wing, and the 26-year-old had an almost instant impact.
Nine minutes into the second half, Edwards picked out Rodrigues with a low cross, and the midfielder finished first-time inside the near post to level the game.
Midway through the second period, Rodrigues headed wide from a Kioso cross moments after a huge call for a penalty for a foul on Goodrham.
There was then an almighty scramble after Mark Harris went through one-on-one, but Kaminski did really well to get off his line quickly and thwart the striker. The loose ball made its way to Rodrigues, who was denied by Kaminski at his near post.
That would prove to be Rodrigues’ final act in a jam-packed display, as Dembele was sent on and immediately drew a red card out of the Hatters.
Walsh, on as a substitute just a minute earlier, was shown a straight red card for a reckless challenge on Dembele with 13 minutes to go.
In the final few minutes, Cumming made a brave save at the feet of Adebayo from a corner, while with the final kick of the ball, Dembele sent a free kick on the every edge of the box narrowly over.
Luton Town (3-4-2-1): Kaminski; Burke, McGuinness, Mengi; Moses, Krauss (Ruddock Mpanzu 51), Nakamba (Walsh 76), Doughty; Clark (Woodrow 76), Brown (Walters 61); Adebayo.
Unused subs: Shea, Taylor, Holmes, Nelson, Johnson.
Booked: Ruddock Mpanzu.
Sent off: Walsh.
Oxford United (4-3-3): Cumming; Kioso, Moore (Long 90+1), Nelson, Brown; Rodrigues (Dembele 74), Vaulks, El Mizouni; Dale (Edwards 46), Harris (Scarlett 84), Goodrham.
Unused subs: Ingram, ter Avest, Long, Sibley, Ebiowei, Goodwin.
Booked: El Mizouni, Moore.
Sent off: None.
Referee: James Bell (West Riding)
Attendance: 11,397 (TBC away)