Andrew Luck faked out the defense, ran untouched into the end zone for a 6-yard touchdown and emphatically threw down the ball with a little extra oomph.
Even he thought it might be a career-best spike.
"It was nice to score," he said matter-of-factly of the moment.
Jim Harbaugh's former quarterback certainly outplayed his current one, and it wasn't close.
Luck passed for 164 yards while facing his college coach for the first time, and the Indianapolis Colts defeated the San Francisco 49ers, 27-7, Sunday at Candlestick Park.
Trent Richardson scored a 1-yard touchdown on his first carry in his Colts debut after being acquired on Wednesday from the Browns. He was drafted two spots behind top-pick Luck last year.
Ahmad Bradshaw added a 1-yard TD run in the final minutes, and Adam Vinatieri kicked a pair of field goals.
Luck kept coming through again to give Indianapolis (2-1) more opportunities.
"I know he's grinning from ear to ear," Colts coach Chuck Pagano said. "I've never seen him smile the way he was smiling after this one."
This marked Colin Kaepernick's his first home loss as a starter.
Frank Gore ran for 82 yards after going for 60 total in his first two games, but there were few bright spots for Kaepernick as San Francisco (1-2) struggled to establish a passing game with tight end Vernon Davis sidelined by a hamstring injury. The defense committed numerous costly penalties for the third straight week.
Luck completed his initial six passes and spoiled the home team's reunion day between coaches on both sides who know each other's tendencies dating to their days at Stanford.
The Colts sure appeared to be better prepared.
Luck sent third-year coach Harbaugh to consecutive losses for the first time. He was happier about the fact his two sisters who attend Stanford got to see him play.
"I wasn't caught up in, 'Oh my gosh, I'm going up against Coach Harbaugh, [Greg] Roman and [Vic] Fangio," Luck said.
"I figured any time you play this sport, coaches and players come and go so much that you always end up going against someone that you played for or played with or had a good relationship with."
Before Sunday, Harbaugh was 7-0 following a defeat -- and Harbaugh faced criticism for playing and starting Aldon Smith two days after the linebacker was arrested and jailed on suspicion of driving under the influence and marijuana possession.
Kaepernick had been 4-0 on his home field since becoming a starter in November. This time, his 49ers were 10 1/2-point favorites, but looked nothing like the better team in getting thoroughly outplayed.
He completed 2 of his 8 first-half passes and wound up just 13 for 27 for 150 yards with an interception and three sacks.
"There's no one thing, we just didn't execute this offense," Kaepernick said.
The 49ers had six penalties for 48 yards and didn't look much better than they did in their five-turnover, 29-3 loss at division rival Seattle last week.
"It's one of those games you look back on down the road and say, 'This was a signature win, maybe one that helped you to do great things, that helped you accomplish the program you built," Pagano said.
• Titans 20, Chargers 17: Jake Locker threw a 34-yard touchdown pass to rookie Justin Hunter with 15 seconds left as Tennessee (2-1) rallied to beat visiting San Diego (1-2). It was their first win against the Chargers for the franchise since 1992 when the team was in Houston.
• Jets 27, Bills 20: Geno Smith threw two touchdown passes, including a go-ahead 69-yarder to Santonio Holmes, as New York (2-1) overcame a team-record 20 penalties to hang on and beat visiting Buffalo (1-2) in an ugly game.
• Lions 27, Redskins 20: Two fourth-quarter bobbles sent Detroit (2-1) past host Washington, dropping Robert Griffin III and the defending NFC East champs to 0-3. Matthew Stafford completed 25 of 42 passes for 385 yards with two touchdowns, and Calvin Johnson and Nate Burleson each had 100 yards receiving for the Lions.
• Panthers 38, Giants 0: Cam Newton threw three touchdown passes and ran for another, and Carolina (1-2) sacked Eli Manning seven times as the host Panthers handed Tom Coughlin his worst defeat as head coach in New York (0-3).
• Saints 31, Cardinals 7: Drew Brees passed for three scores and scrambled for New Orleans' first rushing touchdown of the season, leading the Saints (3-0) past visiting Arizona (1-2). The Saints quarterback was 29 of 46 for 342 yards, with two touchdown strikes to tight end Jimmy Graham.
• Patriots 23, Buccaneers 3: Tom Brady threw two touchdown passes to Kenbrell Thompkins to lead New England (3-0) past visiting Tampa Bay (0-3). Thompkins, an undrafted free agent, scored on plays of 16 and 5 yards in the first half. Aaron Dobson, a second-round draft pick, finished with seven catches for 52 yards.
• Cowboys 31, Rams 7: DeMarco Murray rushed for 175 yards and a touchdown and Tony Romo threw for three scores as Dallas (2-1) beat visiting St. Louis (1-2). DeMarcus Ware had two sacks and broke Harvey Martin's 30-year-old Cowboys franchise record of 114.
• Dolphins 27, Falcons 23: Ryan Tannehill lobbed a 1-yard touchdown pass to rookie Dion Sims with 38 seconds left as unbeaten Miami (3-0) rallied past visiting Atlanta (1-2). The score capped a 13-play, 75-yard drive after Atlanta's Matt Bryant missed a 35-yard field goal attempt with 4:46 left.
• Seahawks 45, Jaguars 17: Russell Wilson matched his career high with four touchdown passes -- two each to Sidney Rice and Zach Miller -- as Seattle dominated as expected in the win against visiting Jacksonville (0-3). Seattle improved to 3-0 for the first time since 2006.