Josh Boyce caught a short pass near the line of scrimmage and turned into a wide-open lane to the end zone to finally give No. 20 TCU the lead against lower-division FCS team Portland State.
The Horned Frogs poured it on after that.
Boyce's 66-yard play was the first of three TCU touchdowns in a span of 1:18 just before halftime. Then, on the first offensive play of the second half, Waymon Jones managed to stay off the ground after getting hit at the line and went 65 yards for another score for the Frogs in their 55-13 victory Saturday.
"We felt it was going to take one big play to get us rolling and it did," quarterback Casey Pachall said. "Once we got the momentum, they weren't going to get it because we couldn't be stopped at that point. That was a little screen play, basically get the ball in his hands and let him do what he can do."
The Horned Frogs (3-1) extended a school record with their 22nd consecutive win at home since 2007, but were tied 3-3 before Boyce's catch-and-run score with 1:55 left in the first half.
Portland State (2-1) took only one snap after that before Drew Hubel's pass was deflected by Jason Verrett and intercepted by linebacker Tank Carder. The Rose Bowl defensive MVP weaved his way for a 26-yard touchdown. And the Frogs still weren't finished before the break.
After the Vikings went three-and-out on their next possession, Skye Dawson had a 42-yard punt return to the 11. Three plays later, he caught the first of his two TD passes, a 10-yarder for a 24-3 halftime lead.
"We're very explosive," said Boyce, who knew there was the chance for a big play when he saw Portland State preparing to blitz and both safeties coming to the line right before the quick screen.
"We got a little greedy and were going to see if we could get after the quarterback," Vikings coach Nigel Burton said. "A great team will make you pay and then we got a blitzkrieg there in a matter of three, four plays. That's what great teams so, they'll jump on you. That's what we talked about afterwards, if you want to be a great team, we have to learn to do that to other people."
James took a handoff to the right to start the second half and was quickly grabbed by a couple of defenders. They pulled him toward the ground, but James rolled over on top of a defender and one of own teammates instead. James then spun away and ran to the end zone, a touchdown that officials quickly confirmed after looking at the replay.
"After I handed it off and carried out my fake, I looked back and I see the little pile, so I think the play is over," Pachall said. "I start kind of looking over to the sideline for the next play and that stuff and all of a sudden Waymon just starts running again."
James, who finished with 136 yards on 10 carries, added an 82-yard kickoff return for a touchdown in the fourth quarter -- the second week in a row the Frogs have returned one for a score.
After Zach Brown's second field goal for Portland State, James fielded the ensuing kickoff at the 18. He took off toward the right sideline, shot through an open gap and picked up a couple of blockers. He then hurdled a falling defender near midfield right in front of the TCU bench and was untouched the rest of the way.
Pachall, who was 14-of-20 for 214 yards with three TDs and an interception, got a fortunate bounce late in the third quarter when his pass was deflected by linebacker Shane Melbo and should have probably been intercepted. Instead, the ball ended up in the hands of Dawson, the former Mountain West Conference champion sprinter. Dawson caught the ball near midfield and outran the Vikings secondary to the end zone for a 73-yard TD.
Portland State came in as the FCS's best rushing team with 348 yards a game but had only 119 yards on 44 carries against TCU. Vikings senior running back Cory McCaffrey, who had run for 291 yards and seven touchdowns the first two games, didn't play because of a swollen knee.
Still, the Vikings opened the game with a 14-play, 71-yard drive that ended with Brown's 22-yard field goal and a 3-0 lead. TCU then scored 41 consecutive points before Brown's 42-yard field goal with 12:40 left in the game, and Portland State didn't get a touchdown until Shaquille Richard scored on a 1-yard run with 1:39 left.
"We came out very strong. We ended up kind of hurting ourselves just kicking a field goal, but it was good to get out early like that," quarterback Connor Kavanaugh said. "Then the defense came out and went three and out. It just shows you how strong we are. Unfortunately, we needed to do that for the full 60 minutes. I definitely think we came out and shocked them."