SANTA CLARA, Calif. — All it takes is one play to turn a team from indifference to anger.

For the San Francisco 49ers, the play occurred on the team's opening drive of the second half while they surprisingly trailed to the upstart Seattle Seahawks — who up until that point had been the more physical team.

However, the 49ers got a jolt of energy when Seattle safety Johnathan Abram unnecessarily pulled at receiver Deebo Samuel's right ankle at the end of a 21-yard pass play on third-and-7 from Seattle's 37-yard line that finished in the red zone.

With his star receiver down on the field and injured, San Francisco head coach Kyle Shanahan was so angry he took to the field to complain to the officials.

"I lost my mind a little bit on that," Shanahan said. "I was real concerned that he was hurt. I didn't like how that looked. I thought it looked pretty bad, the intent of the play. It pissed a lot of people off. It pissed our team off, and you could feel our team react to that after." 

Abram should have been flagged for a personal foul but was not on the play.

"I stayed down a little because I almost lost my temper," Samuel said. "You can see the definition of our team of IGYB — I got your back."  

Tight end George Kittle and other players came to the defense of his teammate as Samuel stayed on the ground, gesturing at an official nearby for the lack of a call. 

"I don't know why you'd want to piss off Deebo," Kittle said. "But if you're going to do that to him, you're just going to piss off Trent Williams, who's one of the scariest people on the football field. 

"You're going to fire up our entire defense and get our whole team fired up, so I don't know what the point of that is. … They gave us another reason to flip the switch even higher, which is what we did." 

As Kittle said, other San Francisco players joined in, and a minor scrum between the two teams ensued, with players pushing and shoving before referees could break it up.

Properly motived, San Francisco took the lead for good five players later a 1-yard quarterback sneak by rookie Brock Purdy, and the 49ers went on to run away from the Seahawks, a 41-23 victory in an NFC Wild Card contest at Levi's Stadium on Saturday afternoon.

With the win, the 49ers will either host the Minnesota Vikings if they defeat the New York Giants on Sunday, or the winner of the Monday Night Football contest between the visiting Dallas Cowboys and the Tampa Bay Buccaneers. 

The 49ers took an early 10-0 lead, then slept-walked through a second quarter dominated by Seattle. The Seahawks outscored San Francisco 17-6 in the quarter, including a 56-yard field goal created by a poorly executed squib kick on a kickoff by San Francisco.

Shanahan was not pleased with his team's performance going into halftime, but the more talented 49ers finally woke up after the Samuel incident. San Francisco scored 25 straight points to open the second half, including a pretty, 74-yard catch and run by Samuel in which fellow receiver Brandon Aiyuk paved the way by sealing off Seattle cornerback Tariq Woolen 30 yards down the field.

Samuel, who missed three games in December with a left knee injury, finished with a team-high six receptions for 133 yards on a rainy day. 

Christian McCaffrey totaled 119 rushing yards on 15 carries, including a 68-yard run midway through the opening quarter. 

The 49ers overwhelmed Seattle in the second half. It's what good teams do, making big plays to destroy an inferior opponent.

But the teams will get better as San Francisco moves deeper in the postseason. The 49ers can't afford to get complacent and let better teams than Seattle hang around for large portions of the game. 

Playing in his first playoff game, Purdy was impressive, completing 18 of 30 passes for 332 yards, with three touchdown passes and no interceptions for a 131.5 passer rating. At 23 years old, Purdy became the youngest player in NFL postseason history to throw for 300 yards and three touchdowns in a game, surpassing his childhood hero Dan Marino. 

Purdy was excited to learn during the postgame presser that NBA star LeBron James had praised him on social media, saying he's got game.

"Lebron said that? Oh, that's sweet," said a smiling Purdy. "That's awesome." 

For a half, the Seahawks showed they could go toe-to-toe with one of the best teams in the NFL. However, San Francisco wrangled control of the game by forcing Seattle quarterback Geno Smith into two turnovers, an interception by Deommordore Lenoir and a strip sack by Charles Omenihu recovered by Nick Bosa with the Seahawks driving to score.

Expected to be one of the worst teams in the NFL, the Seahawks were playing with house money after finishing 9-8 and advancing to the postseason.

"This team is going to be a really great team, and I think the city of Seattle knows it," Seahawks safety Ryan Neal said. "To be honest with you, they should be just freaking excited. If we add a couple more pieces, get back together and get healthy, this team is something to be scared of. There's a very bright future for this organization, for sure."

Eric D. Williams has reported on the NFL for more than a decade, covering the Los Angeles Rams for Sports Illustrated, the Los Angeles Chargers for ESPN and the Seattle Seahawks for the Tacoma News Tribune. Follow him on Twitter at @eric_d_williams.

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