SAN FRANCISCO — Scott Tolzien has earned himself a nickname: “Baby Drew Brees.”

That is what safety Donte Whitner called Tolzien on Sunday, two days after Tolzien’s impressive debut in a 49ers uniform.

“That’s a humbling thing,” Tolzien said of being compared to Brees, the New Orleans Saints’ decorated quarterback. “Brees is someone I look up to and admire, like a lot of quarterbacks do.”

Baby Brees produced the play of the day at Sunday’s Fan Fest at Candlestick Park.

As the 2½-hour practice wound down, Tolzien completed a 10-yard touchdown pass to Mario Manningham in the back, left corner of the end zone during red-zone drills.

No, Tolzien didn’t throw a touchdown in Friday night’s exhibition-opening win over the Minnesota Vikings. But he showed so much more.

“The other day, he looked as good as anyone,” Whitner said.

Tolzien entered Friday’s exhibition after halftime as the 49ers’ third quarterback. It was his first action since the 49ers acquired him off waivers a year ago as an undrafted free agent from the San Diego Chargers, having spent all last season inactive as San Francisco’s emergency quarterback.

“He understands the reads, we can hardly trick him and he knows where to go with the football,” Whitner added.

Tolzien’s opening line: 10-of-13 passing, 84 yards and an interception on his final attempt, which came with him getting hit as he threw.

Of Tolzien’s other two incompletions, one was dropped by rookie Nathan Palmer after Tolzien boldly withstood a crushing hit to his torso by a blitzing safety.

“The safety came from depth, so you know you’ve got time but not all day,” Tolzien recalled. “Honestly, that was the fun part of the game.

“I haven’t been hit in a year. I was sitting in the locker room after, and I have grass stains, and it felt good.”

Tolzien knew this was just the start of a four-game audition that will either keep him on the 49ers roster or advertise his worth to the league’s quarterback-needy teams.

“He’s been real accurate in practice, and in the game,” coach Jim Harbaugh said. “He has good command of the offense and gets the ball out quick.”

Tolzien was Wisconsin’s all-time leader with a career passer rating of 153.2 and helped guide the Badgers to the Rose Bowl after the 2010 season.

After all his inactivity in games, Tolzien said he was ready for Friday’s opportunity, so much so that it “feels like you have answers to a test.”

Whitner wasn’t surprised, and he provided an example of Tolzien’s recent leadership in practice.

“The other day, (Brian) Tyms ran a back-fade (route) and he didn’t run it like Tolzien wanted,” Whitner said, “so (Tolzien) said, ‘Run the route like you want to win it.’

“He’s a leader.”

Tolzien credited his “good-person” vibe to the 49ers organization, starting from “the ownership to the head coach.”

For more on the 49ers, see Cam Inman’s Hot Read blog at blogs.mercurynews.com/49ers. Follow him on Twitter at twitter.com/CamInman.