There was nothing artistic about what went down at the igloo named Solider Field Saturday afternoon, but the Buffalo Bills did the only thing they needed to do: Win the game.

And because they defeated the Chicago Bears 35-13, they are AFC East champions for the third year in a row, and they maintain their tenuous grip on the No. 1 seed in the AFC bracket for yet another week.

The Bills started sluggishly in a poorly played first half, kicked things into gear just long enough in the third quarter to grab the lead, and then slogged it out the rest of the way for their sixth consecutive victory, though coach Sean McDermott will have plenty to discuss with his team given all the mistakes that were made.

Let’s be honest: Had the Bills been playing most other teams as opposed to the now 3-12 Bears, it might have made for a disappointing Christmas that in Buffalo is already being ruined by the blizzard of the century.

What stood out Saturday is that the Bills won with Josh Allen playing one of those games that just make you scratch your head and say, “I thought he was beyond days like this?”

Follow every game: Latest NFL Scores and Schedules

Allen has had a great season, there’s no denying that. It’s scary to think where the Bills would be without him. But he has been unnecessarily careless with the ball at times and this was certainly one of those games.

He threw two more interceptions, both on just absolute bone-headed decisions, now has 13 which is tied for the league lead, and he could have had at least two other picks.

PLAYOFF PICTURE: Who’s in, who’s out and who’s on the bubble?

However, with Allen struggling most of the way, the Bills turned to their running game and hammered the Bears for a season-high 254 yards as James Cook (99 yards) and Devin Singletary (106) ran through gaping holes even though the Bills did not have center Mitch Morse, and then lost his replacement, Ryan Bates, for a short time.

And they relied on a defense that had a terrible first drive of the game, but then played outstanding the rest of the way and made Bears quarterback Justin Fields irrelevant.

Given the brutally frigid conditions, it was easy to predict that this was going to be a struggle for the Bills, and it certainly was in the first half which saw Buffalo trailing 10-6.

On the first series of the game, the Bears marched down the field as if the Buffalo defense was still in the warm locker room. Eight plays, 64 yards, ending with Fields hitting Dante Pettis with a six-yard touchdown pass as the Bills blew a coverage.

Seven of the eight plays gained at least five yards including a 28-yard run by David Montgomery. The Bears even overcame a nullified Montgomery TD run due to a holding penalty.

The Bills answered right back with their only productive possession of the half, a six-play, 71-yard drive which was as easy for them as it was for the Bears offense.

Allen started it with a 24-yard strike to Dawson Knox, Cook ripped off a 24-yard run, and then Gabe Davis got wide open in the left corner of the end zone and hauled in Allen’s 19-yard pass. Here, a woeful day for the Buffalo special teams began in earnest as Tyler Bass missed the extra point.

In the second quarter, Nyheim Hines made a bad decision not to fair catch a punt and the ball rolled to the 2. When the Bills couldn’t get off the goal line, they punted and the Bears had a drive start at the Buffalo 38.

However, the defense stood up and limited Chicago to a 37-yard field goal by Cairo Santos.

The Bills had one more scoring chance late in the half, but three straight Allen incompletions from the Bears 20 forced Bass to try a 38-yard field goal and once again, the wind foiled him and he missed it badly to the right.

It was a different Bills team that emerged from the locker room for the final 30 minutes. Backed up at their own 14 after a Siran Neal penalty wiped out a nice kick return by Hines, the Bills flew down the field in eight plays to take the lead.

Allen hit Devin Singletary for a 10-yard gain to convert one third, he ran 11 yards to convert another, and then Singletary ripped off a 33-yard touchdown run with a great cut near the line to get into the clear. Allen found Khalil Shakir wide open in the back of the end zone for a two-point conversion that made it 14-10.

Moments later, Dane Jackson forced a Montgomery fumble which was recovered by Tim Settle at the Bears 33 and three plays later, Cook broke a 27-yard TD run straight up the middle and Bass’ extra point – after a penalty wiped out a successful two-point conversion pass to Davis – had the Bills up 21-10.

The Bills then had several opportunity to, no pun intended, put this game on ice, but their repeated mistakes that hurt them all day continued. A Spencer Brown holding penalty killed one possession, and then a Davis fumble at the Bears 33 at the end of the third quarter killed another.

And on the next play, Fields hit Jones for a 44-yard gain to the Buffalo 23 and the momentum was clearly on the Bears side, but again, the defense stood tall and Chicago had to settle for a field goal.

From there, the Bills finally dropped the hammer as Allen capped a 56-yard drive with a four-yard TD run, and after a turnover on downs at the Chicago 20, Allen found Knox for a 13-yard TD on a fourth-and-3.

Sal Maiorana can be reached at maiorana@gannett.com. Follow him on Twitter @salmaiorana.