Mikaela Shiffrin attacks the gate during the first run of the giant slalom Thusday. (Michael Probst/AP)

She’d envisioned the moment for the past four years, and then weather delays forced her to wait a couple more days. So when Mikaela Shiffrin reached the bottom of the hill, there was no reason to hide the relief and excitement that suddenly washed over her.

“It was my 15 seconds to let it all out,” she said, “and now I’ve got to focus on tomorrow.”

Shiffrin’s PyeongChang two-step could soon feel familiar — celebrate big win, move on quickly — because she’s taken on an ambitious slate of races at these Winter Games, one that could etch her name in the Olympic history books. The opening act was certainly worth the wait, as the 22-year-old put together a pair of spectacular runs on the giant slalom course Thursday, capturing gold in her first race of these Games.

The win not only erased any uncertainty stemming from an uncharacteristic late-January swoon, but it heightened expectations for what could be a memorable Olympics. Shiffrin will likely race three more times in PyeongChang, including Friday’s slalom race (8 p.m. ET Thursday), and has a shot to join elite company here. Croatia’s Janica Kostelic is the only female skier to win three gold medals at a single Olympics.

“I don’t want to assume that anything else is going to happen,” Shiffrin said. “Every single day is a new day. My only job is to put out my best effort. But going into this Olympics, I thought: ‘Yeah, I could come away with multiple medals. I could also walk away with nothing.’ And now I know that I have something, so that’s a really nice feeling.”

Shiffrin had been considering competing in five disciplines, but her mother said she’ll likely pass on Saturday’s super-G to avoid racing three times in three days. Poor weather postponed two events earlier in the week and condensed the race schedule, and Shiffrin’s team wants to make sure she’s rested and ready for next week’s downhill.

“It is disappointing because it lined up really nicely and we were really excited about the way things were lining up,” said Mike Day, Shiffrin’s coach with the U.S. ski team.

Despite the shuffled schedule, Thursday’s race was exactly as Shiffrin hoped to start her Olympics, a dominant, confidence-building performance that gives her momentum. She’ll defend her Olympic title Friday in the slalom and will enter the race as a heavy favorite. She has reached the podium in every World Cup slalom race she’s finished dating back to December 2014, a stretch that includes 21 first-place finishes.

The giant slalom is a different matter, and Thursday’s win was far from a sure thing. But no one was more consistent or more determined in the two runs down the course at the Yongpyong Alpine Centre.

In her six World Cup giant slalom wins, Shiffrin never had to come from behind to overtake the leader. On Thursday, she faced a 0.20-second deficit after the morning run but then raced the second run nearly four-tenths of a second faster, posting a total time of 2:20.02. The thrilling final run gave her a 0.39-second advantage over second-place Ragnhild Mowinckel of Norway, who took silver with a total time of 2:20.41. Federica Brignone of Italy won the bronze.

Despite the bad weather early in the week, the skies were clear and the wind barely noticeable Thursday morning as skiers assembled at the top of the hill. All eyes were on Shiffrin, especially after fatigue caught up with her and she struggled in late January. Would she look like the smooth, confident racer who reached 11 straight podiums earlier this season? Or the one who finished no higher than seventh in the five races that preceded the Winter Games?

On Thursday morning, she was the seventh skier out of the gate, managing a time of 1:10.82. It was the second-best mark after the initial run and put Shiffrin in great position. Between runs, she was certainly happy with her time but also just relieved to get her Olympics underway.

“It’s been a mental strain the last couple days, thinking we were going to race and then not racing,” she said. “So to finally have the race actually happen today, and I was like, ‘Well, I really hope that I actually can do it when the time comes that we finally race.’ Yeah, I did. Now we got the ball rolling.”

The final giant slalom results are determined by combining times from the two runs, which meant Shiffrin had a bit of ground to make up in the afternoon. Though she trailed Italy’s Manuela Moelgg by 0.20 seconds, some of the other race favorites were stuck further down the leader board, including Germany’s Viktoria Rebensburg, the 2010 Olympic champion who also won bronze in Sochi, and France’s Tessa Worley, ranked No. 2 in the world.

Shiffrin tried to focus on only one run — her own — and knew her first pass through the course put her in good position. Any jitters were shaken loose in the morning. She knew exactly what she needed to pull out to win the second Olympic gold of her young career and had more than four hours to let it roll around in her head.

“There were moments where I thought, ‘I don’t know if I’m good enough to do this,’ ” she said. “And then there are moments where I thought, like, ‘Who cares? You gotta try. You’re here.’ ”

She took a nap and did a couple of runs down the men’s course. Her mother could see Shiffrin transform, steeling herself for the final run and slowly putting on her mental battle armor. “She just made up her mind to put it out there the second run,” said Eileen Shiffrin, who also serves as one of her daughter’s coaches. “She seemed really pretty confident the second run.”

Her second run time of 1:09.20 was the day’s fourth-fastest, and she became the first American to win the woman’s giant slalom at an Olympics since Julia Mancuso in 2006. While the slalom is her best discipline — her lone Olympic title, in fact, until Thursday — in many ways, the giant slalom was the ideal one to open her Olympics, giving her confidence before the race schedule gets too hairy.

“I love slalom, but GS is something that I have this love-hate relationship with that makes it a bit sweeter to have that performance today,” she said.

She finished fifth in the giant slalom at the Sochi Games but steadily improved in the technical discipline in the four years that followed, winning six giant slalom races on the World Cup circuit and reaching the podium 13 times. She finished second at last year’s world championships, instantly becoming one of the favorites for PyeongChang.

Shiffrin was ranked third in the world in the event entering these Olympics but hadn’t stood on a giant slalom podium since a victory Jan. 6, in Kranjska Gora, Slovenia. Her most recent giant slalom race was Jan. 27 in Lenzerheide, Switzerland, where she finished a disappointing seventh.

Shiffrin was supposed to have completed her two best events by Thursday, but heavy winds prompted officials to push the giant slalom to Thursday and the slalom to Friday. Shiffrin said she wasn’t too worried about which was first; she was just eager to get these Olympics started.

And now the rest of the Alpine world is eager to see just what else she has in store.