The Giants were 12-point underdogs coming into Sunday night's game against the Broncos in Denver. The line made sense, too; they were 0-5, had lost starting wide receivers Odell Beckham Jr. and Brandon Marshall for the season, starting cornerback Dominique Rodgers-Cromartie was suspended for insolence, and two other starters -- defensive end Olivier Vernon and wideout Sterling Shepard -- wouldn't play because of injuries.

So naturally, all the Giants did was dominate pretty much the entire game, jumping out to a 17-3 halftime lead before a previously unseen running game and a beleaguered defense took over in the second half en route to a 23-10 win for the Giants.

The NFL is weird.

Oh, by the way: The other 12-point underdog won this week too -- the Dolphins overcame a 17-point deficit to beat the Falcons in Atlanta. So I guess we shouldn't be surprised when the Giants and Dolphins meet in the Super Bowl. You heard it here first. 

Back on Earth, here are six takeaways from the Giants' 23-10 win over the Broncos.

Where did that Giants running game come from?!

New York came into the game with the 23rd-ranked running game, according to Football Outsiders. Denver, meanwhile, ranked first against the run. Not only that, but the Broncos were playing at home, which meant that the Giants would presumably struggle with crowd noise, the snap count, rhythm and what whatever else ails the timing of an efficient running game.

Instead, the Giants ran the ball for 148 yards, including 117 yards on 21 carries from Orleans Darkwa. In four previous outings this season, Darkwa combined for 122 yards, and never gained more than 69 yards in a game.

This 47-yard gallop early in the second quarter ...

... set up Eli Manning's first touchdown pass of the night:

Added bonus: Evan Engram finally has a role! It made a lot of sense when the Giants drafted Engram in the first round this spring, but he had struggled to find his niche through the first month of the season. Perhaps fewer pass-catching options simplified things for both quarterback and tight end but whatever the reason, Engram looked comfortable in Denver. He finished with five catches for a career-best 82 yards and the aforementioned touchdown.

Added bonus, part II: The Giants much-maligned offensive line also had its best game of the season. Justin Pugh moved from left guard to right tackle, and his ability to contain Von Miller and Shaq Barrett meant that other players could help left tackle Ereck Flowers, who has been blamed for just about everything that has gone wrong with the Giants' season to date. 

And guess what? For the most part it worked! Yes, Manning was sacked three times, but the running backs averaged 4.9 yards per carry. And the success on the ground meant that the Giants only needed to throw the ball 19 times all night.

In related news ...

Ben McAdoo gives up playcalling duties 

It took five straight losses and some of the saddest offensive football you'll ever see but head coach Ben McAdoo, who has also served as the play caller since 2014, relinquished those duties on Sunday night to offensive coordinator Mike Sullivan. The results: As efficient a performance as the Giants have had all season. 

At halftime, NBC's Michelle Tafoya asked the coach about the decision. If you were expecting some "this offense needed a jumpstart" type explanation McAdoo didn't provide it. 

"Because entire team needed me this week," he said, after injuries and suspensions seemed to occupy most of McAdoo's free time in recent days. 

Whatever the reason, Sullivan certainly appeared up to the task; he took it to one of the league's best defenses. And should he keep the gig next week too, things don't get any easier next week when the Giants host the Seahawks.

The Giants' defense makes an appearance too

The Giants came into the season not just as many people's pick to win the division, but with the expectation that their defense would have a lot to do with it. The unit showed glimpses of that promise early before things went south in recent weeks. Apparently nothing galvanizes a team like suspensions and injuries because the Broncos' offense couldn't move the ball for most of the evening. Jamaal Charles was the team's leading rusher with 17 yards, and quarterback Trevor Siemian put the ball up 50 times but managed just 29 completions.  

Well, 31 if you count the two he threw to the Giants ...

... including a huge pick-six just before halftime:

And even without Vernon, the Giants' front four were menaces; Siemian was sacked four times, three courtesy of Jason Pierre-Paul.

About Trevor Siemian

If 2015 first-round pick Paxton Lynch wasn't sidelined with a shoulder injury, and if the conversation wasn't about possibly putting him on injured reserve, you'd have to imagine we'd be talking about a quarterback controversy in Denver right now. Sieman hasn't been Osweiler-ian terrible, but he hasn't been great, either; coming into Sunday's game he ranked 23rd in total value among all passers, just behind -- wait for it -- Eli Manning.

Siemian had his moments against the Giants:

But Siemian was never in any real danger of leading the Broncos back into the game either. He completed a season-low 58 percent of his throws against the Giants, and it was the fourth time in five games he had a completion percentage below 62 percent.

Incidentally, Brock Osweiler did make an appearance late in the first half. Siemian appeared to injure his non-throwing shoulder while trying to tackle Janoris Jenkins following his second interception. Osweiler came in, went 2 of 4 for 18 yards, and promptly returned to the bench after Siemian was cleared to return at the start of the third quarter. 

Also not helping Siemian and the Broncos' offense: the kicking game. Brandon McManus honked an eminently makeable field goal attempt and had another blocked. Typically, you'd expect the team to bring in competition because you never know how and when a kicker will lose his confidence. But don't expect McManus to go anywhere, even if he's now missed five field goals at home. We say this because just before the start of the season the Broncos signed him to a three-year extension worth $11.25 million, including more than $8 million in guarantees. 

Ewing Theory, NFL edition

Remember the Ewing Theory? It was created in the mid-1990s by Dave Cirilli and popularized more than a decade later by Bill Simmons. The gist goes like this: Patrick Ewing's teams, both at Georgetown and the Knicks, were somehow better when he wasn't on the court. On the surface, it's a ridiculous notion but one that held some truth too -- not just with Ewing, but across other sports. 

We mention that because of this tweet from Deadspin's Drew Magery from early in Sunday night's game:

The only reason anybody would try to convince themselves that the Giants are better without Beckham is if they also happened to own the team and didn't want to have to pay him close to $20 million annually. Otherwise, there's absolutely no rational explanation for thinking anything close to this. (Unless, of course, you're on Twitter. Then all takes, no matter how ridiculous, matter.)

Up next

The Broncos (3-2) blew a great chance to make up ground on the Chiefs (5-1) in the AFC West. Kansas City dropped its first game of the season on Sunday against Pittsburgh but are a game and a half up on Denver, who will play in Los Angeles against the Chargers next week.

The Giants (1-5) will host the Seahawks (3-2), who are a half-game behind the Rams in the NFC West. It's not all unicorns and rainbows in New York, however. Yes, they may be off the schneid, but they're four games behind the division-leading Eagles.