For the most part, the window for more FCS-over-FBS upsets has closed in 2016 as both levels now turn to the meat of their respective schedules that feature even more top 25 matchups and opportunities to jostle for better position in the rankings.

Week 5 is an indication of this turning of the calendar as many top FCS teams are presented with some interesting challengers this week that are sure to provide another shake-up in the standings.

Here are the top four FCS games to tune into this week:

Cal Poly vs. North Dakota – Saturday at 2 p.m.

Quarterback Dano Graves had four touchdowns in Cal Poly's upset over Montana last weekend.
Cal Poly Athletics
Quarterback Dano Graves had four touchdowns in Cal Poly's upset over Montana last weekend.
No. 18 Cal Poly is on the rise after jumping into the top 25 for the first time this year last week following its 42-41 upset over then-No. 6 Montana to move to 3-1 on the year.

Meanwhile, upset-minded North Dakota (2-2) looks for a similar jump this week after the Fighting Hawks fell only three spots short of a ranking this past week.

MORE: FCS top plays of Week 4

Cal Poly continued to run wild  with 274 yards and a trio of touchdowns on the ground against Montana last Saturday (the Mustangs came into last week averaging 400 rushing yards per game). The victory marked the third straight game Cal Poly has tallied 38 or more points.

But that offensive strength will be tested against a Fighting Hawks defense that’s only allowed 113.8 rushing yards per game so far and limited Montana State to 15 points last week.

The Mustangs proved last week that their offense can run past a solid defense in Montana. If North Dakota wants to move over .500, it will have to do a better job of corralling Joe Proteroe and company in the Mustangs backfield.

North Dakota State vs. Illinois State – 2 p.m.

Illinois State has dropped two straight games since defeating Northwestern.
David Banks | USA TODAY Sports
Illinois State has dropped two straight games since defeating Northwestern.
Illinois State has quickly tumbled since its early-season upset over the Big Ten’s Northwestern that catapulted the Redbirds into the top five after Week 2.

Following the big victory came consecutive gut-wrenching three-point losses to Eastern Illinois and Indiana State. Now at 2-2, Illinois State needs a bounce back.

That rebound win will be anything but easy to come by, however, as next on the Redbirds’ docket is No. 1 North Dakota State.

The Bison, coming off a bye in Week 4, escaped Iowa City with a road upset over the No. 13 Hawkeyes for one of the greatest FCS-over-FBS upsets in college football history two weeks ago.

NDSU’s defense led the way in the 23-21 stunner as MJ Stumpft started the day’s scoring with a first quarter pick six and the Bison’s unit went on to hold the Hawkeyes to a single touchdown over the final half of play.

NDSU will look to generate similar impact plays against an efficient Redbirds offense led by the arm of Jake Kolbe (25-of-32, 258 yards, three touchdowns and no interceptions in last week’s loss).

It will take a lot for Illinois State to upset the unanimous No. 1 team this weekend, but pulling it off would be an excellent way to get back in the win column.

Sam Houston State vs. Stephen F. Austin – Saturday at 4 p.m.

Sam Houston State boasts the FCS' best passing offense and eighth-best rushing offense.
Sam Houston State Athletics
Sam Houston State boasts the FCS' best passing offense and eighth-best rushing offense.
The No. 1 offense in the nation in Sam Houston State continued to put up points last week as it cruised by Houston Baptist 52-16.

But Stephen F. Austin (3-1) is no slouch with the ball either as it’s scored more than 30 points in each of its previous five outings.

Jeremiah Briscoe and his 345 passing yards per game leads Sam Houston State’s air attack while Remus Bulmer anchors its eighth-best rushing unit in the nation. The two combined for 493 yards of offense and five touchdowns last week.

RELATED: FBS games to watch in Week 5

Meanwhile, Stephen F. Austin’s Hunter Taylor threw for 376 yards and four touchdowns himself to lead the Lumberjacks’ dynamic passing offense.

It will be an old-fashioned Texas shootout this weekend between the two programs, which should be an entertaining spectacle.

Montana vs. Southern Utah – Saturday at 4:30 p.m.

Southern Utah entered the top 25 this week and sits at No. 24.
Southern Utah Athletics
Southern Utah entered the top 25 this week and sits at No. 24.
Montana took a small hit from its previously-discussed loss to Cal Poly, dropping out of the top 10 to No. 11 in the latest Coaches poll. On the opposite end, Southern Utah’s second-straight win last week moved the Thunderbirds into the top 25 at No. 24.

The Grizzlies don’t put up a lot of points or yards on offense and were held to just 67 rushing yards in last week’s loss. But Montana's defense has led the team to early success, including a 20-14 upset over Northern Iowa two weeks ago.

And while Southern Utah posted 50 points on Portland State last week, it too doesn’t rely on outscoring teams as it ranks 50th in the nation in total offense – 11 spots below Montana.

So expect Saturday’s late afternoon matchup to be a low-scoring battle where the turnover margin and field position decide the outcome.