The Hatters were held to a goalless draw by a Rotherham side fighting for their Championship lives in the final home game of the season at Kenilworth Road tonight.
Elijah Adebayo came closest to breaking the deadlock for Town, rattling the post in a first half in which the visitors were also denied by the woodwork, Matt Crooks' lob bouncing back off the upright into Simon Sluga's hands as the point guaranteed the Hatters at least 12th place and a top-half finish for the first time since 2005/06.
Manager Nathan Jones made two changes, with Dan Potts making his first start for the Hatters since he suffered an injury in the first half of the Swansea City defeat back in March.
Ryan Tunnicliffe started in midfield alongside Glen Rea, who scored in the 1-1 draw versus Middlesbrough at the weekend, as Town looked to extend their unbeaten run to six matches.
In an even start to the game, both sides had attempts on target - Kiernan Dewsbury-Hall firing straight at visiting keeper Jamal Blackman, before Lewis Wing's 30-yard deflected free-kick had Simon Sluga diving low to his right and holding on to a ball that skidded off the greasy surface.
Dewsbury-Hall was next to have a go for the Town as Rotherham struggled to clear a James Bree corner, but his curling effort from just inside the area wouldn't bend back enough to creep inside the far post.
Then, as the half developed into a end-to-end affair, it was Millers midfielder Ben Wiles who cracked a 25-yarder that Sonny Bradley threw himself in the way of before the Hatters ploughed forward again in the 21st minute and Elijah Adebayo rattled the upright with a powerful half-volley on 21 minutes.
Rotherham went close in the 25th minute when Ryan Giles' cross from the left found Michael Smith in the middle, but his glancing header was a whisker wide of the far post, seconds before Adebayo was making inroads on the Town right, arcing in an inviting cross that just eluded Collins and Potts in the six-yard box.
Sluga was his reliable self again to gather a low cross-shot from Matt Crooks, and still we hadn't played half-an-hour! Down the other end, Dewsbury-Hall's corner from the right almost ended up directly in the back of the net, but for Blackman's reaction save against the post.
The Hatters broke quickly again when Bradley picked out Adebayo with a raking ball from left to right, bur Bree - racing through the middle - couldn't get a shot off, then neither could the striker and finally Collins was forced too far wide.
A quieter spell followed, but it was Rotherham's turn to his the woodwork four minutes before the break when Crooks latched onto Smith's flick, but his looping lob over Sluga bounced up against the post and into the keeper's grateful arms.
Dewsbury-Hall fizzed another shot just wide in first-half injury-time, before Jones added more attacking flair at the break with Cornick on in place of Potts.
There was little goalmouth action in the opening quarter of the second half, and Jones withdrew Collins to introduce Mpanzu with 63 minutes gone, and it was the substitute's driving run into the box that led to a chance for Adebayo almost immediately, but Blackman was well positioned to hold onto the striker's attempted curler.
Millers sub Chiedozie Ogbene made a similar impression on 68 minutes, skipping inside Naismith and Cornick but driving his shot straight at Bradley, defending the Town six-yard box as well as he had all night.
Giles stood up an inviting 73rd minute cross that Crooks rose at the far post to meet, but thankfully fot the Hatters his header flew past Sluga's left post.
Matty Pearson sent a header on target from Dewsbury-Hall's deep free-kick, just as Jones brought Kazenga LuaLua on in place of Tunnicliffe, then Mpanzu rattled the scoreboard above the Oak Road goal after Dewsbury-Hall's run towards the Millers' box had been halted by a clean tackle by Wood.
The on-loan Leicester midfielder was pulling the strings in the middle of the park, and he was again at the heart of the Town's next attacking move, with Naismith this time firing over, right-footed, from 20 yards out.
Wing forced Sluga into another save from a free-kick with four minutes of normal time remaining, before the Hatters broke at lightning pace from the resulting corner, Cornick feeding Bree to set Adebayo up for a shot on the run that once again flew high into the Oak Road stand.
A grand-stand finale was short-lived as Bradley's header in the 92nd minute was swiftly ruled out by referee David Webb, despite replays suggesting a foul in the area may have been a harsh judgement.
Nevertheless, the point took the Hatters up to 62 for the season ahead of the final match of the campaign against Queens Park Rangers on Saturday.
Town: Sluga; Bree, Pearson, Bradley (C), Potts (Cornick 46), Naismith; Tunnicliffe, Rea, Dewsbury-Hall; Collins (Mpanzu 63), Adebayo
Substitutes: Shea, Cranie, Cornick, Moncur, Mpanzu, LuaLua, Nombe, Morrell, Pereira
Rotherham: Blackman, Olosunde (Ogbene 65), Harding, Wood (C), Ihiekwe, Giles, Barlaser (Mattock 74), Wiles, Wing, Crooks; Smith (Ladapo 65).
Substitutes: Johansson, Mattock, A.MacDonald, S.MacDonald, Lindsay, Sadlier, Jozefzoon, Ogbene, Ladapo.
Referee: David Webb