Eagles coach Nick Sirianni tried to show us how smart he is. His arrogance cost his team a victory. | Mike Sielski

Quez Watkins had beaten his man and blazed down the sideline for a 91-yard completion from Jalen Hurts, and DeVonta Smith had drawn a pass-interference penalty in the end zone on a cornerback, Josh Norman, who had signed with the 49ers just on Labor Day. First-and-goal at the 1-yard line for the Eagles. First-and-goal at the 1-yard line, with a chance to take a 10-point lead in the second quarter Sunday.

First-and-goal at the 1-yard line, and Nick Sirianni decided to get cute.

So on first down, Hurts rolled right, Zach Ertz flashed open, and Hurts’ pass sailed behind him. And on second down, the 49ers swarmed Miles Sanders for a three-yard loss. And on third down, the Eagles reeling now, Hurts gained just one yard on a scramble to the right. And on fourth down … a handoff to Smith, who pitched the ball to wide receiver/emergency quarterback Greg Ward on a reverse, who heaved the ball out of the end zone. The Philly Ordinary.

It’s quite an accomplishment to orchestrate a drive that includes a 91-yard play and doesn’t result in any points. But Sirianni, in his second game as an NFL head coach and play-caller, managed to pull it off, and if he’s smart, the turning point in the Eagles’ 17-11 loss will serve as a hard lesson learned. The Eagles’ offensive players trudged off the field after Ward’s incomplete pass, the 49ers went 97 yards in 12 plays, taking the lead just before halftime on a Jauan Jennings touchdown catch, and the energy at Lincoln Financial Field — for the Eagles’ first home game with fans in nearly two years — left in a slow leak. The game was gone, then and there, and Sirianni had only himself to blame.

“I don’t think I called good plays in that area,” he said. “There are going to be times when you’re going to look at it and be like, ‘Yeah, I want those calls back.’ When they work, it was a good play. They didn’t. It was my fault. I didn’t call good enough plays there. I didn’t put the players in good enough positions. But we’re all in this together, coaches and players.”

» READ MORE: The Jalen Hurts-Nick Sirianni marriage off to an uneven start after listless Eagles’ loss to the 49ers

From his earnest, insightful answers at his press conferences to the Eagles’ easy victory over the Falcons last week in Atlanta, Sirianni had gone a long way to erasing the effect of the shaky first impression he made in January, of his nervous, tongue-tied introduction here. Sunday, though, showed a new and different flaw for him to fix: the arrogance of a coach who refuses to take the most direct or conventional route to success.

He used all three of his second-half timeouts in succession with more than 5 minutes left in regulation, arguing later that he was trying to leave the Eagles enough time to score quickly and assure themselves an additional offensive possession. Maybe the math behind that strategy is sound in the abstract, but the practical ramification Sunday was that, just by getting one first down, the 49ers melted away the game’s final 3:58, because the Eagles had no way to stop the clock. By then, though, the real damage had already been done.

“We could have done a lot better there in the first half, especially on the goal line,” right tackle Lane Johnson said. “We had opportunities to punch it in for touchdowns, and we didn’t. When you play a good team like that, it’s the difference between winning and losing.”

In the best of those opportunities, the simplest of approaches would have sufficed. Hurts is 6-foot-1 and 223 pounds and plays behind one of the NFL’s best offensive lines. The proper play call on first-and-goal from the 1, given those conditions and circumstances, is a quarterback sneak. It’s also the proper play call on second down, third down, and fourth down. No muss, no fuss, and little chance to lose much yardage.

Yet Sirianni, who had Hurts sneak for a touchdown later in the game, argued that the line of scrimmage was too far away from the goal line to try a sneak in the second quarter — a flimsy justification for a series of decisions in which he seemed bent on showing everyone just how smart he was. On fourth down, he was counting on the 49ers’ playing of a particular coverage — probably man-to-man — that would be vulnerable to a trick play. But the slow-developing sequence delivered none of the surprise of its forerunner from Super Bowl LII. Asked if he was Ward’s intended target on the play, Hurts nodded. A quarterback catching a touchdown pass from a receiver … that’s old news and a tired strategy around here and throughout the NFL.

» READ MORE: Birds’ stalled drives in first half prove costly in home-opening loss

“The play looked good in practice last week,” Sirianni said. “Felt confident in the coverage we were getting. Hey, they didn’t play it. That happens sometimes. On second thought, do I want that play back? Of course.”

He’s a young coach, growing on the job, and it’s fair to give him a grace period here, but one that’s only so long. A victory Sunday would have meant the Eagles’ first 2-0 start in five years and, at minimum, a one-game lead over every other team in the NFC East. Instead, the Eagles will head to Arlington for next Monday night’s game against the Cowboys without Brandon Graham, likely without Brandon Brooks, and without the cushion in the standings and the confidence that would have accompanied a win over the 49ers. First-and-goal at the 1-yard line came and went without a point, and now everyone will look at Nick Sirianni with a little more skepticism, with a little less patience for the rookie to prove himself. Now we’ll start to find out what kind of head coach he really is.