The world's top golfers are heading to Naucalpan, Mexico, this week for the 2018 WGC-Mexico Championship. Defending champion Dustin Johnson is the Vegas favorite at 13/2, followed closely by Justin Thomas at 15/2 and Jon Rahm at 10/1. Johnson opened at 6/1 before slipping slightly.

Before you make any bets or enter a daily fantasy golf tournament on DraftKings or FanDuel, you'll want to hear what the team at SportsLine has to say.

SportsLine's prediction model, built by DFS pro Mike McClure, was all over Tommy Fleetwood at the Honda Classic. Despite being a 25/1 long shot, the model projected him to be a top contender. The result: Fleetwood shot 70 or better in all four rounds and finished in fourth place. Anybody who used their model had plenty of great value selections to choose from.

Now that the field for the 2018 World Golf Championships event is locked, SportsLine simulated the event 10,000 times and the results were surprising.

One huge surprise the model is calling for at the WGC-Mexico Championship: Paul Casey, a 25/1 long shot, makes a serious run at the title. He's a target for anyone looking for a huge payday.

Casey is coming off a disappointing performance at the Genesis Open that saw him fail to break 70 in a tournament for the first time this year. However, he has been hot this season with three top-12 finishes in five starts, including a seventh-place showing at the CIMB Classic after shooting a 77 in the opening round.

Casey is No.1 on the PGA Tour in sand save percentage at 66.67, recording 18 saves in 27 bunkers. He's also accurate, with a 68.82 driving accuracy percentage (17th on tour) and a 71.67 greens in regulation percentage (19th). He has an Official World Golf Ranking of 17.

Another curveball: Bubba Watson, who has three top-three finishes at the WGC-Mexico Championship in the past four years, doesn't sniff the top 12. He's somebody to completely steer clear of this week.

Watson's driving accuracy percentage of 54.83 ranks outside of the top 150 on the PGA Tour and he's recorded just two eagles in 414 holes, barely good for the top 100. Prior to his Genesis Open win, Watson finished 35th at the AT&T Pebble Beach Pro-Am and 40th at the Waste Management Phoenix Open. He was cut at the CareerBuilder Challenge.

Also, four additional golfers with odds of 20/1 or longer are positioning themselves to make a serious run at the title. Anyone who bets on these underdogs could hit it big.

So who wins the 2018 WGC-Mexico Championship? And which long shots stun the golfing world? Check out the updated odds below and visit SportsLine now to see the full projected leaderboard from the model that has been red-hot so far this season, and find out.

Dustin Johnson 13/2
Justin Thomas 15/2
Jon Rahm 10/1
Jordan Spieth 12/1
Tommy Fleetwood 16/1
Rickie Fowler 16/1
Phil Mickelson 20/1
Justin Rose 20/1
Alex Noren 25/1
Sergio Garcia 25/1
Paul Casey 25/1 
Patrick Cantlay 30/1
Tony Finau 30/1 
Bubba Watson 30/1
Thomas Pieters 30/1
Tyrrell Hatton 40/1