A goal in each half from Andrew Shinnie and Harry Cornick secured another victory to extend the unbeaten league run to 11 matches, including ten wins, in a game that saw the Hatters have to ride their luck at times.
The second-placed Town are on a terrific run, however, and including FA Cup matches the run now stands at 13 unbeaten - including 12 wins - with a ninth clean sheet in that sequence meaning just four goals have gone past keeper James Shea since the defeat at Barnsley on October 13th.
Boss Nathan Jones was forced into the first change to his starting line-up for nine matches, as Glen Rea's absence through injury brought Jorge Grant back into the side.
Rea had to be substituted in the first half of Saturday's home win over Burton, and wasn't fit to take his place in the team.
Grant, who replaced him in the 2-0 win over the Brewers at Kenilworth Road, came in for his first start since the Accrington Stanley game on October 23.
Alan McCormack came onto the bench along with Lloyd Jones, who replaced Dan Potts, as the second-placed Town looked for a seventh straight league victory at the club who sat in 21st place, one inside the relegation zone, at kick-off.
In Rea's absence, and with club captain Alan Sheehan on the bench, Sonny Bradley wore the armband.
The Hatters started brightly, with Shinnie and Stacey both getting in on the right only to see low cut-backs intended for Collins intercepted, either side of Lee dragging his right-footed shot wide after some neat link-up play with Cornick on the edge of the area.
Scunthorpe started to find their feet after a shaky opening ten minutes, however, and saw volleys from Yasin Ben El-Mhanni and Lee Novak fly over the bar, before the latter fired straight at Shea from 18 yards in the 16th minute.
Funso Ojo was the next to have a go for the Iron, who were enjoying the better of the half, on 21 minutes, but once again Shea was equal to his shot from outside the area.
Rory McArdle headed Cameron Borthwick-Jackson's free-kick wide on the half-hour, then the Hatters almost took the lead against the run of play in the 34th minute.
Lee picked the ball up just inside his own half and found Cornick free on the right. After a perfect first touch to set himself up, the forward let fly from just inside the box only to find home keeper Jak Alnwick there to deny him a seventh goal of the season with a good save.
The breakthrough came in the 37th minute when Justin, who had just crossed for Pearson to head wide, nicked the ball in front of Ben El-Mhanni and burst down the left, then playing a lovely sideways ball across the D.
It reached Shinnie, who had drifted inside from the right, and the Scotsman bent a left-footed shot first time into the bottom corner from just outside the area, for his fifth goal of the season.
United tried to respond, Ojo blasting well off target from distance, but the Hatters had a half-time lead for the ninth game in a row, even if on this occasion it was against the run of play.
The lead was doubled five minutes into the second half when Lee pounced on an error in the hosts' defence and cracked a shot on goal that Alnwick could only parry into the path of Cornick, who smashed in his seventh goal of the season from close range.
Inevitably it brought chants of 'Last Christmas' from the travelling fans behind that goal, and almost immediately Lee came close to extending the lead, but his attempt at turning Pearson's header in from close range was blocked.
Lee was soon leadng the charge again, attempting one of his trademark curlers into the far corner from the left side of the area after Grant and Cornick had combined to set him free from deep inside their own half, but this one was deflected wide.
Shea made a point-blank save from a Kyle Wootton header with quarter-of-an-hour to go, just before Jones - who had already brought McCormack on for Grant - introduced Hylton for Cornick.
Within two minutes of his arrival, Hylton had caused havoc in the home area to win a corner, and then, after Bradley had headed Justin's delivery back across goal, he unleashed a right-footed volley that flew inches wide.
The same corner routine, Justin picking out Bradley at the far post, almost brought reward with four minutes left as Hylton attempted to get his head on the centre-half's header, but Scunthorpe managed to smuggle the ball away.
Fifty points for the season now. Safe from relegation and eyes pointing upwards, with the Town now one point off top spot and with a four-point cushion in the automatic promotion places, and 11 for the play-offs. A wonderful 2018 is ending very nicely for the Town!
Onto Walsall away on Saturday...
TOWN: Shea, Stacey, Pearson, Bradley (c), Justin, Mpanzu, Shinnie (Berry 90), Grant (McCormack 65), Lee, Collins, Cornick (Hylton 77). Subs: LuaLua, Jones, Sheehan, Stech
Yellows: Collins
GOALS: Shinnie 37, Cornick 50
SCUNTHORPE: Alnwick, Borthwick-Jackson, Ojo, Perch, Novak (Humphrys 82), Thomas, Ben El-Mhanni (Dales 83), Goode, Sutton, McArdle (c), Wootton. Subs: Flatt, Horsfield, Ugbo, Lewis.
Yellows: Perch
REFEREE: Martin Coy
ATT: 4,050 (766 Hatters)
