OLYMPIC VALLEY, Calif. (AP) — Mikaela Shiffrin covered her mouth with her glove in disbelief after crossing the finish line. Finally believing, she tossed her right ski pole into the air.

Usually so stoic, the American standout let her emotions loose. With good reason: This was a victory on U.S. snow.

Shiffrin used a strong burst near the end to win a giant slalom race as the World Cup returned to Squaw Valley for the first time since 1969. She finished in a combined time of 2 minutes, 16.42 seconds on a warm Friday, eclipsing Federica Brignone of Italy by 0.07 seconds.

Tessa Worley of France was third, 0.86 seconds back. Worley’s lead over Shiffrin in the season-long GS standings shrank to 80 points with just one event remaining in the discipline

This was Shiffrin’s fourth career World Cup GS win — not a bad early birthday present.

“I just knew that no matter what, I have to attack like crazy,” said Shiffrin, who turns 22 on Monday. “All these girls are going for wins. I’m so happy with how that went today.”

In addition, Shiffrin increased her lead in the race for the overall World Cup title to 278 points over Slovenia’s Ilka Stuhec, who crashed in the first run. Sofia Goggia of Italy moved into third place and is 366 points behind Shiffrin with five races left.

Goggia had one of the more entertaining final runs of the afternoon when she hit a gate and lost her left ski pole. She quickly recovered and didn’t miss a beat as she finished seventh.

Worley could’ve clinched the GS crystal globe with a victory. It was weighing on her mind.

“For sure, it is some pressure,” said the 27-year-old Worley, who won a GS competition at Killington, Vermont, in November. “Before every race, before every run, I’m trying to clean my mind and stay focused on the main thing — and the main thing is to ski.

“If I don’t ski, I don’t get anything. I’m trying to ski as fast as I can. I have no regrets this season. We’ll see if it goes how I want it to go or not.”

Shiffrin will put off any celebrations for a few days. There’s too much work ahead. The Olympic slalom champion has a slalom race Saturday at Squaw Valley before heading to Aspen, Colorado, next week for the World Cup Finals.

When asked about her post-race exultation, Shiffrin said she did that because, “I’m in the USA.” She then screamed to the partisan crowd: “You guys are so awesome! Thank you for coming out here!”

It’s been a banner season for Shiffrin, who earned her 30th career World Cup win. She also won her third straight slalom title at world championships last month.

Now, she’s trying to join some elite company in Phil Mahre, Tamara McKinney, Bode Miller and Lindsey Vonn as the only Americans to win the overall crown.

“Even having a 270-something lead going into the last (five) races, that’s big,” said Shiffrin, who captured a GS title at Squaw during the 2014 U.S. championships. “At same time, I don’t feel like I’ve done anything yet. Try not to take it for granted.”