NEW ORLEANS — Philadelphia Eagles defensive coordinator Vic Fangio had never beat Patrick Mahomes. He was 0-8 against Mahomes and the Kansas City Chiefs.

He obviously learned something through all of those losses.

Fangio’s defense and how it destroyed Mahomes was the story of the first half of Super Bowl LIX, with the Eagles taking a 24-0 lead into the locker room. They harassed Mahomes, shut down everyone else and then took a huge lead with a massive defensive play. Eagles rookie cornerback Cooper DeJean picked off Mahomes on a bad decision to pass it over the middle after he’d been sacked two straight times. DeJean returned it 38 yards for a touchdown.

At that point the Eagles led 17-0. And the Eagles defense alone led the Chiefs offense 7-0. The Chiefs didn’t have a great offense in the regular season, but it’s rare to see them get completely dominated. They were getting dominated early in the Super Bowl by a very good Philadelphia defense. It got even worse when linebacker Zack Baun intercepted Mahomes at Kansas City’s 14-yard line with 1:45 left in the half. That led to an A.J. Brown touchdown. The implosion of the Chiefs, especially on offense, was stunning.

The Eagles had experienced something similar to Sunday’s first half two years ago. They led 24-14 at halftime of Super Bowl LVII, with Mahomes limping off the field late in the second quarter due to a bad ankle injury. It looked like the Eagles were going to take that game. The Chiefs came back to win. So nothing was decided at halftime.

But the Eagles defense had just played one of the greatest halves ever seen in a Super Bowl.

Some controversial calls early

After so much talk about officiating and how the Chiefs were on the right side of an inordinate amount of calls, there was a controversial moment almost immediately. The Eagles went for it on fourth down on their first drive, and Jalen Hurts threw a pretty deep pass to Brown. Brown caught it for a 32-yard gain, but Brown was called for a very questionable pass interference penalty. The Eagles punted.

The Eagles got one back. On a third-down incompletion, an unnecessary roughness penalty was called on Chiefs cornerback Trent McDuffie for hitting Eagles tight end Dallas Goedert late and high. Instead of the Eagles having to decide what to do on fourth-and-5 at the Chiefs’ 42, they had a first down at Kansas City’s 27. Jahan Dotson looked like he had a touchdown on a deep catch two plays later, but he was ruled down at the 1-yard line. The Eagles are nearly automatic in that situation, and their Tush Push got Hurts the first score of Super Bowl LIX.

The Eagles were driving again when Hurts made a big mistake. On a third-and-10, with the Eagles in field goal range, the Chiefs blitzed and Hurts hurried a deep throw. It was well short to Brown, and Chiefs safety Bryan Cook picked it off at Kansas City’s 2-yard line. The Eagles defense bailed out Hurts by forcing a quick three-and-out, but it was still a missed opportunity for at least three points.

It didn’t really matter. Philadelphia was playing so well, particularly on offense, that it could absorb a terrible interception by Hurts. By halftime, nobody seemed to even remember it.

Chiefs have trouble moving the ball

When the Eagles took a 10-0 lead with 8:38 to go in the first half they were thoroughly ahead on the stat sheet. Philadelphia had 151 yards to just 24 for the Chiefs, who had held the ball for only 4:58. The Eagles had it for 16:20.

The avalanche continued. The Eagles had back-to-back sacks on Mahomes right after taking that 10-point lead. Then came the DeJean pick 6 and the Eagles were up big.

Nothing went right for the Chiefs in the first half. When it looked like the defense would finally get a big stop, linebacker Nick Bolton was called for unnecessary roughness for hitting Saquon Barkley after a pass fell incomplete. That cost the Chiefs some time to get some points on the board before halftime. Then Mahomes threw his second interception of the game, on a pass that Baun made a nice diving catch on. Brown scored on a 12-yard catch shortly after and the Eagles were in control.

The Chiefs had an astonishing one first down in the entire first half, and that came on their first offensive play of the game. They finished the half with just 23 total yards, compared to 179 for the Eagles. Mahomes was 6 of 14 for 33 yards, no touchdowns, two interceptions and a microscopic 10.7 passer rating. It was the fewest yards by the Chiefs in a first half since Mahomes took over as their starting quarterback.

On the biggest stage, with a historic third straight Super Bowl championship on the line, Mahomes played one of the worst halves of his NFL career. Fangio seemed to have finally figured out how to get the best of his nemesis.