SANTA CLARA, Calif. — Brock Purdy, amped after another score, jogged toward the San Francisco 49ers sideline, stopping short in an open space. And did his dance.

He normally pulls out “The Dougie” when he gets into the end zone. But the something-from-nothing highlight he pulled off deserved a jig. So the quarterback did it.

Teach me how to Dougie.
Teach me-teach me how to Dougie.
Errybody love me.
Erry-errybody love me.

“He can do The Dougie, ‘The Stanky Leg,’” offensive tackle Spencer Burford said. “He can hit whatever dance he wanna hit. Whatever works. Whatever gets him in that mode.”

The play: a naked bootleg in the third quarter, with the game tied at 28. It didn’t quite fool the Chicago Bears’ defense, but it created enough misdirection for fullback Kyle Juszczyk to get a few yards. Except Brock Purdy didn’t throw it.

Instead, he continued scrambling toward the left sideline. Improvising.

“I was hoping,” 49ers coach Kyle Shanahan said, “he would throw it to him right away. … And then he didn’t do it. So then I was just hoping he was going to throw it away so we could have a couple more downs.”

Purdy slowed, backed up and circled back toward the middle of the field, eluding the pursuit of Bears defensive lineman Austin Booker. Bears defensive tackle Andrew Billings followed on Booker’s heels, but Purdy shifted again, cutting upfield toward the end zone, splitting both defenders. Refusing to settle.

Having already scrambled for two touchdowns, he seemed on his way to a third, and the defense gravitated toward him, expecting the same. But Purdy, after 8.56 seconds of juking Bears, spotted Juszczyk alone near the end zone pylon. Just before crossing the line of scrimmage, Purdy flicked an easy touchdown pass to his fullback.

“Just his ability to extend the play is, I think, something that’s so special,” Juszczyk said. “He’s just a natural playmaker. … Incredible. Absolutely incredible.”

Purdy schooled the Bears’ defense as part of a larger lesson. A reminder of a truth already proven but often forgotten, or just obscured by his occasion for a dud performance.

His best elevates the 49ers to Super Bowl-worthy. For as low as his floor can seem, his ceiling is higher.

Sunday, in the biggest game of the year, he showed up as that Purdy — the one who had the 49ers one throw from a Super Bowl ring. This version can beat any defense. This version injects life into this team, an intoxicating confidence that spreads from the huddle to the sidelines to the buzzing sea of red at Levi’s Stadium.

As soon as the expectations rose for the 49ers, and the stakes escalated, Purdy ascended with them. The season got real, transforming from a surprising feel-good story to a real chance to put themselves in the driver’s seat. The 49ers stared at a critical three-game slate to close the season and lock up the No. 1 seed. In the first two games, Purdy threw eight touchdown passes and ran in another two while orchestrating 90 points.