Reid finished the three-heat race in two minutes 47.70 seconds. She was just 0.03 seconds ahead of Hollingsworth, the reigning world champion from Eckville, Alta.
Marion Thees of Germany took the bronze. Katie Uhlaender of the United States finished fifth, a half-second behind after posting the fastest time in Friday's lone heat.
Reid beat Hollingsworth by the same margin — 0.01 — in each heat to win the first World Cup medal of her career. Her best previous finish was sixth. The first two runs were held Thursday.
“I am over the moon. There was so much excitement at the track and it was so loud at the start line that I just fed off that,” said Reid.
“I was surprised leading after yesterday, but I always felt like I’ve known that I’m capable of sliding with these very talented girls.
"This tells me that I can be there too and I’m pretty stoked,”
Martins Dukurs of Latvia won the gold medal in the men's event earlier Friday, edging brother Tomass by 0.08.
Alexander Tretiakov of Russia won the bronze, 0.17 behind the winner.
Olympic gold medallist, Jon Montgomery of Russell, Man., made his return to the World Cup after taking last year off by finishing 12th.
Hollingsworth said her silver on Friday was secondary to the Reid’s golden accomplishment.
“Today was all about Sarah,” she said. “Going up the track I told Sarah that everyone here, including me, is rooting for you to win. I am just so incredibly happy for her.”