Scotland striker Lyndon Dykes suffered an injury as QPR ended a promising campaign with a 3-1 victory at home to Luton.
Stefan Johansen and Albert Adomah scored after Kiernan Dewsbury-Hall's equaliser had cancelled out Charlie Austin's opener.
It meant the west London side finished ninth in the Sky Bet Championship table and will hope to challenge for promotion next term.
But Scotland boss Steve Clarke will be alarmed that Rs striker Dykes picked up what looked like a knee injury - potentially worrying news ahead of the European Championship.
Dykes, who scored six times in the final eight matches of the season, was hurt by a crude challenge by Glen Rea just before the interval and limped through the final seconds of the first half but did not appear for the second.
Austin had put QPR ahead after 20 minutes following a burst forward from the back by central defender Jordy De Wijs - his eighth goal since joining on loan from West Brom in January for a second spell at Loftus Road.
Dewsbury-Hall attempted to cut out Johansen's ball in from the left but succeeded only in heading it towards Dykes, who nodded it down for Austin to finish from near the edge of the six-yard box.
Luton responded strongly to going behind and George Moncur, Harry Cornick and Dewsbury-Hall saw shots deflected wide before Rangers goalkeeper Seny Dieng produced a stunning save.
Sonny Bradley nudged Dewsbury-Hall's left-wing free-kick towards goal but Dieng showed superb reflexes to push the ball on to the post.
But Dieng could not prevent Luton drawing level two minutes before half-time.
He parried Moncur's shot but was unable to keep out Dewsbury-Hall's right-footed follow-up despite getting a hand to the ball.
However, Johansen restored the lead with his fourth goal since arriving on loan from Fulham.
Ilias Chair collected Yoann Barbet's pass and calmly set up Johansen, who slotted past keeper Simon Sluga.
The visitors rarely looked like finding another equaliser, although Luke Berry had a left-footed effort saved by Dieng and Hatters left-back Kal Naismith shot inches over.
Substitute Adomah sealed the win by tapping into an empty net in stoppage time after being teed up by Chris Willock.
QPR's form since January has been excellent, but the turnaround has largely been inspired by Austin and Johansen.
Their chances for next season seem to hinge on retaining them along with young players such as Dieng, Chair and defender Rob Dickie, who might well attract interest from other clubs during the summer.
What the managers said...
QPR's Mark Warburton: "For Lyndon to go down - he never goes down and he's as hard as a piece of teak. But I don't think the doctor was too concerned and Lyndon was desperate to come back onto the pitch because he thought he was OK. The doctor said he wanted to be cautious, and we'll always listen to the medical staff. So that was more precautionary, I hope.
"It was a really pleasing end to the season to get three more points and take us to 68, which is 10 more than last year. I'm delighted for the players. It's not a huge success, because we haven't won anything, but we're only two points off of seventh and the players deserve so much credit for the way they've worked hard and shown character."
Luton's Nathan Jones: "I thought after the first half that we should have been out of sight. We had enough opportunities to kill the game. But in the second half we didn't really get going. I'm proud of the performance but we didn't show enough quality in moments and that's the level - if you don't take your chances and put teams to bed they will hurt you.
"We're finding our feet at the level and wanted to establish ourselves as a Championship side and we've done that. We've finished 12th and if we'd been able to win today we'd have finished 10th. We've had a season of fantastic relative success. It's been a very productive season to finish where we have, with 62 points, and never where our budget tells us we should be. In over half the games we've got a positive result and that's why we're in the position we are and not in a final-day scrap."