Kansas runner Joe Moore and Olivia Pratt won the men's and women's races at the 2019 Bank of America Shamrock Shuffle 8K race.
Daniel Romanchuk, who won the 2018 Chicago Marathon, and Susannah Scaroni both took the crown in the wheelchair races.
Moore sprinted to the finish line in a tight race and finished with an unofficial time of 23 minutes, 18 seconds - just five seconds before fellow Kansas runner James Wilson.
"[Wilson] made the race," Moore said.
"The two of us went hard and pushed it from the front. It was a good time," Wilson said as the duo shared a finish line moment together.
Moore has run the shuffle in previous years but never won.
"I've run it a few times, gotten third, gotten fifth and won it!" he said.
Pratt, who also ran the race in 2018, finished with an unofficial time was 26 minutes, 26 seconds.
"I love this city so it’s so fun to get to come down here and run my heart out on these streets," she said.
Romanchuk finished with an unofficial time of 16 minutes and 29 seconds and Scaroni finished in 19 minutes and 2 seconds.
Thousands of runners took to city streets to celebrate the unofficial start of outdoor running season this weekend.
The 40th annual race took participants on a grand tour of downtown Chicago, finishing and ending in Grant Park.
Notable names kicked off the race this year, including Olympian and American record-holder Deena Kastor, who won the 2005 and 2009 Shamrock Shuffle. she finished in eighth place in the women's race with an unofficial time of 27:12.
Carey Pinkowski, the race's executive director, also joined runners this year to help raise money for youth-based initiatives.
"The Bank of America Shamrock Shuffle underscores the spirit and diversity of Chicago’s running community, a community that has helped us build an iconic event like the Bank of America Shamrock Shuffle and a global phenomenon like the Bank of America Chicago Marathon," said Pinkowski. "And with the ongoing growth and development of our charity programs, these events have continually given back to communities across the world. It is an honor this year to run on behalf of four organizations making a profound difference in the lives of Chicagoans."
And you can't forget the race's unofficial mascots, "The Green Guys." In honor of the Shuffle's 40th year, they took off their costumes to tell NBC 5 the story of how the group got its start.