Sunday's 33-17, season-opening win over the Seattle Seahawks didn't come easily, however.
The 49ers needed Ted Ginn Jr. to end the fourth-quarter suspense by scoring two touchdowns within 59 seconds, first by returning a kickoff 102 yards and then a punt 55 yards.
Never before in 49ers history had two special-teams returns produced touchdowns in a game. That historic feat allowed them to finally relax, something Harbaugh didn't do on the eve of his debut.
"I slept like a baby last night - I woke up every hour crying, making sure these guys were prepared in every way," Harbaugh said. "They had our back. The players did a heck of a job. I'm really proud of them."
The 49ers defense walloped the youth-laden Seahawks throughout the first half, and although Seattle rallied, the 49ers finished strong. On the Seahawks' final snap, Parys Haralson delivered his second sack, and it forced a fumble that Patrick Willis recovered with 55 seconds remaining.
That defense produced five sacks, three turnovers and much-needed support.
Offensively, the 49ers sputtered. They converted only 1 of 12 third downs. Running back Frank Gore managed 59 yards in 22 carries. And David Akers' four field goals defined the 49ers' poor execution inside the Seahawks' 20-yard line.
But quarterback Alex Smith played efficiently in a once-unfathomable return to Candlestick.
"I don't know about vindication," Smith said. "It's 1-0. That's great. That's the biggest thing for a quarterback: The bottom line is getting a win."
Smith finished 15-of-20 passing for 124 yards with no interceptions and a 90.4 passer rating, which is his career best in four opening-day starts.
"We got in the red zone multiple times, and we need to walk away with some touchdowns," Smith said. "I don't know if it necessarily was a conservative game plan. It's the way the game went."
The 49ers defense had a simple strategy, too. Instead of blitzing their heart out under new coordinator Vic Fangio, their defensive front simply bulled over a Seahawks line that included three first-time starters.
Ray McDonald and Justin Smith produced third-down sacks to snuff out the Seahawks' first two series. In a fitting bookend, Tarvaris Jackson got sacked again to curtail Seattle's final two series of the game, with Smith and Haralson doing those honors.
"The game plan was to stay in our rush lanes and get good pressure on them, and we did that," McDonald said. "Vic put the onus on us to get there and put the pressure on the quarterback. We appreciate him for that."
The Seahawks were outgained 128-37 in the first half. But Jackson threw an 8-yard touchdown pass to Golden Tate on their first series after halftime.
The 49ers' lead suddenly got cut to 19-17 with 3:56 left in the game when Doug Baldwin, one of Harbaugh's pupils at Stanford, scored on a 55-yard catch-and-run.
The 49ers' counterattack: "It was the Ted Ginn Show," wide receiver Michael Crabtree said.
On his kickoff return, Ginn started up the left hash marks and cut right at the 15-yard line past Leon Washington. While racing down the right sideline, Ginn briefly held the ball in the air before looking on the stadium's video board and seeing safety Earl Thomas in hot pursuit.
"I thought about just putting (the ball) back in my arms, secure it across the goal line for a touchdown and secure the victory for us," said Ginn, who locked up that win even further by darting up the spine of the field on his punt return.
Last weekend, Ginn was agreeing to slash his salary from $2.2 million to $1 million. He had been slated as a potential starting wide receiver, but his only action there came on an end-around run for no gain.
His 268 return yards, however, rank first in 49ers history. And they clinched the first win in Harbaugh's brightening tenure.
"You go into the first game, and you don't have - at least I didn't have - a real grasp of what the team is. Now we have a better handle," Harbaugh said. "We knew there'd be some things we really liked and some things we didn't."