You could sense the tension at Levi’s Stadium Sunday the moment rookie Isaac Guerendo fumbled the second half kickoff and the New England Patriots quickly scored on a 5-yard touchdown pass from Jacoby Brissett to Austin Hooper.

A game the 49ers had led 20-0 was suddenly 20-10 and it was hard not to think of the previous week’s collapse against the Los Angeles Rams, which was fueled in part by special teams errors.

The usual script called for quarterback Brock Purdy to restore order as he usually does — with a series of short, safe completions and a time-consuming drive that would put the Patriots back on their heels.

Instead, Purdy dropped back then dropped a perfect 53-yard rainbow into the arms of Deebo Samuel over Jonathan Jones.

Three plays later, Jordan Mason scored on a 4-yard run, the 49ers led 27-10 and order had been restored in an eventual 30-13 victory.

This was yet another side of Purdy, who week by week is proving to be one of the NFL’s best quarterbacks. Call this version Bombs Away Brock, as Purdy repeatedly attacked the Patriots downfield, completing 15 of 27 passes for 288 yards and a 12-yard touchdown pass to George Kittle.

That’s a gaudy 19.2 yards per completion, and they weren’t of the run-after-catch variety. Teams are wise to the 49ers attacking underneath with shallow crosses and the like, and have schemed their defenses to defend against it.

“In this game, there were a couple of plays where their safeties were low and we had guys going deep with Deebo and J.J.,” Purdy said. “We talked about it on the sideline and let it rip and I trust those guys to get under it and they did. It was nice to connect on those deeper routes, get those on tape and give us some confidence moving forward with the deep ball.”

Besides the 53-yard pass to Purdy, there was a 45-yard strike to Jauan Jennings, 38 yards to Brandon Aiyuk and a 32-yarder to Jennings. For a day at least, dink and dunk gave way to the vertical game. Purdy is more than a year removed from internal brace elbow surgery, has worked diligently to strengthen his arm and it’s clear he’s got all the zip he needs, and then some, to complete any route that is asked of him.

The 45-yard pass to Jennings against Marcus Jones was actually defended well, but the pass was a thing of beauty and virtually impossible to drop.

To hear coach Kyle Shanahan tell it, nothing Purdy does surprises him. Purdy has been his quarterback for 30 starts including the postseason. He’s learned there’s not a play he can’t call because Purdy isn’t physically up to the task.

“I think Brock, since his first game playing here, he’s good in the dropback game, the play-action game, bootlegs and stuff,” Shanahan said. “Brock has been one of the most consistent players in the league since he started playing.”

Seeing Purdy throw accurate rainbows puts defenses in a bind. If he can win over the top as easily as underneath, and attack midrange as well, it makes the 49ers passing game dangerous on every blade of grass.

“People scheme us up, and they do a good job of creating leverage and taking away certain routes, and for us it’s a good opportunity to adapt and work on different things,” Purdy said. “Every team creates a different challenge. This week was a lot of man coverage and they did a good job funneling everything back to the middle of the field.”

Purdy’s touchdown pass to Kittle came against three defenders on a route that was originally designed to be run from the 40-yard line. Kittle was skeptical, but kept his feelings to himself.

“The play was for him to break out and go up,” Purdy said. “It was more of a third-down play but we got the look down there. I saw him break out, I was getting hit, so I thought I just need to give my guy a chance. Just put it up for him. He made a great play — way better than the throw.”

The deep shots are only part of Purdy’s burgeoning skill set. As he displayed in last year’s playoffs, Purdy is more and more comfortable getting first downs with his feet. He measured off two perfect first-half scrambles — seven yards on third-and-3 and five yards on third-and-4 — to keep a drive alive for a 26-yard field goal by Jake Moody to open the scoring.

Last week, Purdy ended up with 10 rushes, and it’s not like Shanahan is dialing up read option plays.

“I’m not going to act like I’m going to throw and then run to make a play,” Purdy said. “It’s not like that. I’m still a quarterback. I’m trying to go through my reads and hit my guys and move the chains. That’s the position I play and I take pride in that. . . . I feel like I have just the right amount of athleticism to make plays. I don’t need to be a freak athlete. I know who I am.”

The 49ers by now are amused when Purdy’s ability is disparaged in any way.

“He’s the best, man,” middle linebacker Fred Warner said. “I love how he plays the game, the leader that he is. He doesn’t say a lot but he doesn’t have to. He’s so humble in his approach and he’s continuing to get better in all phases of his game, knowing what it takes to win.”

It wasn’t perfect. Purdy was too bold with a late interception in the end zone by Jabril Peppers on a pass intended for Aiyuk, a play for which he took full responsibility.

“I think I hitched to him two or three times, which just isn’t good as a quarterback,” Purdy said. “I got greedy and Jabril made a play.”

Kittle and the 49ers will forgive the occasional mistake because it signifies the confidence Purdy has in his receivers.

“The deep ball he threw to Jauan, he just has trust in us to go out and make plays,” Kittle said. “We have a lot of talented players, a lot of guys who can catch a football. We have a lot of guys that he just trusts.”