Steelers vs. Colts takeaways: Indy, behind Joe Flacco, holds on to hand Pittsburgh its first loss of season

Indianapolis came up with the necessary plays to upset Pittsburgh

Joe Flacco is still good enough to beat the Pittsburgh Steelers. Flacco, the longtime Raven who replaced injured starter Anthony Richardson in the first half, threw a pair of touchdowns to help lead the Colts to a 27-24 upset win over Pittsburgh. 

Flacco entered the game late in the first quarter after Richardson exited for a second and final time after taking multiple hits to the midsection by Steelers safety Minkah Fitzpatrick. Flacco threw a touchdown pass on his first drive and helped the home team build a 17-0 lead. 

After a slow start, Justin Fields and the Steelers offense got on track in the second half, as Fields scored three touchdowns that included two on the ground. But the Flacco-led Colts twice responded to Pittsburgh scores with scores of their won, as the home team never relinquished its lead. 

Indianapolis clinched its second straight win when Pittsburgh went three-and-out on its final drive. The Steelers offense was ultimately done in by a botched center-QB exchange that led to a 12-yard loss on its final drive. 

Flacco finished the game with 168 yards on 16 of 26 passing. Fields threw for a season-high 314 yards, but he was sacked four times and committed a costly fumble that took the Steelers out of field goal range midway through the third quarter. 

Here's a closer look at how the Colts upset the Steelers. 

Why the Colts won 

The Colts, despite rookie center Tanor Bortolini making his first career start in place of injured perennial Pro Bowler Ryan Kelly, had early success on the ground against Pittsburgh's formidable run defense. Jonathan Taylor rumbled for 88 yards and a score despite leaving the game early with an ankle injury. That success on the ground enabled Richardson to get off to a hot start as the Colts took a quick 7-0 lead. 

Indianapolis didn't slow down when Flacco took over the offense. Like Richardson, Flacco received solid pass protection (T.J. Watt didn't record a sack for the first time this season) that allowed him to dissect Pittsburgh's secondary. The biggest beneficiaries of this were wideouts Michael Pittman (six catches for 113 yards) and Josh Downs (8 catches for 82 yards and a score). 

Defensively, the Colts also received stellar play from backups with defensive end Kwity Paye and Kenny Moore II out with injuries. The Colts defense stonewalled Najee Harris to just 19 yards on 13 carries while often forcing Pittsburgh into third-and-long situations. 

Why the Steelers lost 

Once again, the Steelers started slow before finding their rhythm, but unlike the previous three weeks, Pittsburgh wasn't able to make up for time lost on Sunday. The Steelers will have to figure out a way to get off to faster starts if they are going to be a legitimate contender in the AFC. 

Mistakes, something the Steelers managed to largely avoid during their 3-0 start, were also an issue. Down 17-3 late in the first half, George Pickens coughed up the ball after getting to the Colts' 5-yard line. Fields, as alluded to earlier, had two costly fumbles: the first occurring after he was sacked that negated a 30-yard punt return by Calvin Austin III and his muffed snap that derailed Pittsburgh's final drive. 

Another big miscue was Joey Porter Jr.'s dropped pick in the end zone early in the second quarter. Instead of a momentum-turning pick, Pittsburgh's deficit swelled from 14 to 17 points.

There are no moral wins, but Steelers coach Mike Tomlin should feel good about the adjustments Fields and the offense made in the second half. While Fields wasn't sharp early, he played looser, took more changes and was effective with his legs while directing three straight drives that ended with touchdowns. Fields (who led Pittsburgh with 55 yards on 10 carries) continued to strengthen his rapport with Pickens, who had seven catches for 113 yards. Tight end Pat Freiermuth also emerged with 57 yards and a score. 

Turning point 

There's no question that the turning point was when Flacco replaced Richardson for good with 3:58 left in the opening quarter. Despite not playing at all during the season's first four games, the 39-year-old Flacco looked to be in midseason form. He finished that drive with a touchdown pass to downs and led the Colts on another scoring drive the next time they had the ball. 

Play of the game 

Ahead 17-10, Flacco ended the third quarter by completing a 25-yard completion to downs on a third-and-7 play. The completion helped set up Flacco's touchdown pass to tight end Drew Ogletree that extended the Colts' lead. 

Quotable 

What's next 

The Steelers will return home to face the 2-2 Cowboys on "Sunday Night Football." The Colts will embark on a two-game road trip against division foes, starting next Sunday with the 0-4 Jaguars.