The 2021 U.S. Open heads for Round 4 on Sunday with some surprising names on top of the leaderboard. Mackenzie Hughes, Louis Oosthuizen and Russell Henley are tied for the lead at 5-under par. That trio is being chased by some of the biggest names on the PGA Tour as Rory McIlroy and Bryson DeChambeau sit two shots back at 3 under, while Jon Rahm (-2) and Dustin Johnson (-1) are among the other stars still in contention. 

William Hill Sportsbook lists Oosthuizen as the favorite at 15-4 in the 2021 U.S. Open odds fro Sunday, followed by McIlroy and DeChambeau -- both at 5-1. 

We simulated the final round of the 2021 U.S. Open 10,000 times, and there are some MAJOR surprises.

Our proprietary model, built by DFS pro Mike McClure, has been RED-HOT since the PGA Tour resumed in June. In fact, it's up well over $9,000 on its best bets since the restart, nailing tournament after tournament.

At the 2021 Masters, McClure nailed Jon Rahm's (+250) top-five finish, as well as Corey Conners' (+550) top-10 showing. McClure's best bets netted over $450 at the Masters.

In addition, McClure was all over Daniel Berger's win at +1400 in his best bets at the AT&T Pebble Beach Pro-Am in February. McClure also nailed Viktor Hovland's (+2500) victory in the Mayakoba Golf Classic in December. That was one of many huge calls he's made in the past few months. He also finished profitable at the 2020 U.S. Open, nailing two of his best bets, including a +1100 top-five bet on Matthew Wolff.

This same model has nailed a whopping six majors entering the weekend. Anyone who has followed it has seen MASSIVE returns!

One major surprise the model is calling for on Sunday at the 2021 U.S. Open: Oosthuizen, a major champion and the top Vegas favorite, stumbles all the way out of the top five! Another surprise: Jon Rahm, a 12-1 long shot, makes a strong run at the title. He's a target for anyone looking for a HUGE payday.

Also, the model is targeting FOUR golfers with odds of 25-1 or longer who will make surprising runs, including a MASSIVE long shot higher than 50-1 who cracks the top 10! Anyone who backs these long shots could hit it BIG.

So who wins the 2021 U.S. Open? And which HUGE long shots are a MUST-BACK? ... Join SportsLine right now to see who you can bank on to win the 2021 U.S. Open, and see which long shots make a run at the title, all from the model that is up well over $9,000 on PGA picks since the restart!