Jordan Storey and Daniel Jebbison struck a goal in each half to give high-flying Preston a 2-1 victory at Oxford and a fourth win in their last eight away Championship games.
Storey headed in Thierry Small's cross from four yards out at the far post in the 26th minute following a corner. The ball appeared to deflect in off Ciaron Brown's back but Storey was claiming it.
Canada international Jebbison then notched his fifth goal of the season as he converted Alfie Devine's cutback four minutes into the second half.
Oxford halved the deficit four minutes later when Brian De Keersmaecker beat a defender from Nic Prelec's pass and hammered home a left-footed drive, but Preston held on to their lead.
North End manager Paul Heckingbottom had to watch from the stands due to a ban, so his assistant Stuart McCall was the Lillywhites' main man on the touchline.
U's head coach Gary Rowett gave striker Ole Romeny a first start of the season and continued with Michal Helik, Ben Davies and Brown as his three centre-halves.
After a cagey opening, Preston engineered the first opening as unmarked Harrison Armstrong headed Pol Valentin's right wing cross past the left upright.
United responded with a spell of pressure that saw Greg Leigh's far post volley deflect wide, and from the corner Leigh directed a header at goal that keeper Daniel Iversen comfortably saved below his crossbar.
Oxford were wasteful with their final pass on several attacks, and when the visitors went in front through Storey, it stunned the home crowd.
Only a last-ditch interception by Brown then prevented Lewis Dobbin doubling the lead a few moments later.
United had their moments before half-time, though, with Will Vaulks seeing a long-range shot saved and Michal Helik's volley deflecting over after a Vaulks long throw.
Brown's far post header at a corner was superbly tipped over his bar by keeper Iversen just before the break.
Rowett made an attacking substitution during the interval, replacing Hidde ter Avest with the pacy Stan Mills at right wingback.
However, North End doubled their lead with a swift raid down the right, neatly converted by Jebbison.
De Keersmaecker's powerful strike after 53 minutes gave the U's renewed hope, and it needed another fine save by Iversen to keep out Will Lankshear's shot as the home side pressed for an equaliser.
It started to become nearly all Oxford. Lankshear headed Mills cross against the bar and substitute Tyler Goodrham's shot from 20 yards deflected wide but Preston were able to weather the storm
Oxford's Gary Rowett:
"Looking back at the starting formation, I probably got that wrong and I take responsibility for that.
"We didn't do enough in the first half with that system. I kept the continuity in some areas and made some changes to get a little more creativity in some areas but it didn't quite work.
"It was a very winnable game for us and that's what adds to the frustration. They're in and around the top because they do the right things consistently in games. We keep just doing the wrong things in games and that's the challenge for us.
"When you concede poor goals, it makes it so difficult. Teams don't need a helping hand. They get a free header back post for the first one. The second goal is just a little bit of movement around the box from wide players which we just need to deal with.
"We dominated possession after that and the stats. We had 24 shots with eight on target and I think they've had two shots on target, two goals. That's been the difference in the game.
"Small margins tend to go against us rather than go for us. We're also lacking a little bit of belief compared to last season and it's my job to find an answer to that."
Preston assistant Stuart McCall:
"Today the result was better than the performance.
"I think we were a bit patchy, but you have to look at Oxford's record against the big boys here, it's a difficult place to come and they load the ball in your box.
"The timing of that second goal straight after half-time was important, though we'd have liked it much better had we not given a goal away straight after.
"But, yes, that second goal was a nicely worked goal, good football, good goal.
"Then their goal soon after was a great strike by the lad, fair play to the boy. That was annoying because it came from our throw-in, we gave it away cheaply.
"We talk about that a lot. A lot of goals come from throw-ins, just as much as corners - as Oxford themselves know - but we gave it away cheaply.
"It could have been a little bit more comfortable had we not conceded straight away but that second one was a good time to score.
"I always think it's a worry when you've got someone like Will (Vaulks) hurling the long ones in, and we were without Liam Lindsay who was suspended. He's one of those that gets his head on everything.
"Dan (Iversen) had a couple of good saves but we expect that of him now, he's a good goalkeeper.
"I've had a chat with Paul (Heckingbottom) afterwards and he's delighted with the win, naturally. I've told him he's got to start behaving because I need him back out on the touchline!"
