The 24-year-old Australian slowly climbed up the Utah general classification until he was sitting fifth going into the final stage – the Park City loop that ended with the 12.4km climb up Empire Pass and a technical 8.8km descent in the rain to the finish.
Haig launched an attack on the lower slopes of Empire Pass that only race leader Sepp Kuss (LottoNL-Jumbo) could follow, then held on when Kuss rode away from him, finishing third on the stage and climbing to third overall behind Kuss and Ben Hermans (Israel Cycling Academy).
"Sort of following the form of all the previous stages, I knew that the big differences were made down at the lower altitudes of all the climbs," Haig said. "So today I tried to make a difference at the bottom of the final climb."
Haig dispatched all but Kuss with his accelerations, and then the pair went after Nathan Brown (EF Education First-Drapac) – the lone survivor from the early breakaway. But once the duo had Brown in their sights, Kuss jumped away from Haig, caught and passed Brown and then soloed into Park City for his third stage win of the race.
Haig, meanwhile, fell back into the first chasing group that also included Hermans, Brent Bookwalter (BMC Racing), Hugh Carthy and Joe Dombrowski (EF Education First-Drapac) and Keegan Swirbul (Jelly Belly-Maxxis).
"On the descent, Brent and I sort of worked a little bit together and got a bit of gap on one of the little rises before the proper descent down into town," Haig said.
From there, it was a breakneck descent as Haig held on while Bookwalter, who has raced down the descent many times, guided them through the slippery conditions as rain started to fall for the finale.
"We went quite fast, and it wasn't that much fun descending that quickly coming into Park City in the rain, but that's racing," Haig said.
Bookwalter and Haig clawed their way back to within eight seconds of Kuss, but the duo was unable to stop the race leader from taking his third stage win of the week. Bookwalter nipped Haig at the line for second, and Haig grabbed third as Carthy came in for fourth another 19 seconds back.
It wasn't the result Haig may have been hoping for on the final stage, but it lifted him onto the overall podium. Maybe the best result Haig got in Utah, however, was the preparation he put in for the Vuelta a Espana, which starts later this month.
"I was in Park City for two weeks before the race," Haig said. "It was great preparation for this race and getting used to the altitude and the American time zone, but also preparing for the Vuelta. I think it's perfect preparation to do a big altitude block here.
"The racing is super-nice and I love being in America," he said. "It's a bit of a refreshing change from being in Europe. I think it's ideal preparation, and I think Sepp can probably say the same. Hopefully he does well at the Vuelta, too."