Olympic swimmer Matt Grevers proposes to Annie Chandler at Missouri Grand Prix.

Rarely has so much depended on U.S. Olympic swimmer Matt Grevers earning spot on the medal stand. Thankfully, everything went according to plan for Grevers on Saturday. After winning the gold in the 100-meter backstroke at the Missouri Grand Prix on Saturday night, the 26-year-old pulled off a surprise marriage proposal to his girlfriend, and USA national swimming teammate, Annie Chandler... on the medal stand.

Chandler, 24, placed the medal on Grevers and walked out of the way as the ceremony continued. She walked back over to him after the silver and bronze winners left the stand following some photos. The unsuspecting Chandler then stood up on the stand with Grevers when he dropped to one knee, stunning her as well as the crowd with a public proposal.

She immediately said yes.

According to the Associated Press, Grevers' older brother Andy sneaked his sibling the diamond engagement ring.

"I took it out a little fast because my heart was racing the whole time," he said. "If I didn't get first it wouldn't have worked out so well."

Grevers won a gold medal in the 2008 Olympics as a preliminary relay swimmer and a silver in the 100 meter backstroke.