Overend, who was celebrating his 56th birthday, pulled away less than two miles into the 7.6-mile ascent and rode to the victory in 55 minutes and three seconds.
Juarez, 50, took the runner-up spot just over a minute later with Timothy Ahearn third at 3:19.
“It’s good to win,” said Overend as he cooled off at the summit. “I wanted to win, and I wouldn’t travel this far for it if I didn’t think I had a chance. Comparing past times with the others, I figured I should be the favorite, but I’m not getting any younger!”
It was the second consecutive runner-up finish for Juarez, who finished second to Nico Toutenhoofd in 2010.
“I had more confidence today,” said Juarez. “I knew what to expect. When Ned pulled away, though, I knew he was going to take it. Once you get a decent gap here, it’s hard for anyone to make it up on you. I love this climb!”