With 31 Grand Slam titles between them, the world takes notice when Novak Djokovic and Rafael Nadal share the tennis court. When it happens in a Grand Slam final, the interest is intensified ten-fold, even when it doesn't start until the wee hours of the morning. The 2019 Australian Open men's singles final will pit these two legends against each other on Sunday at 3:30 a.m. ET. Djokovic is a six-time Australian Open champion and the world's No. 1-ranked player, while Nadal has one Australian Open title and entered this year's tournament as the No. 2 seed. The last time they met in this setting back in 2012, they thrilled fans with a nearly six-hour, five-set thriller that Djokovic won. This time around, Djokovic is a -135 favorite (risk $135 to win $100), while Nadal is +115 as the underdog (risk $100 to win $115) in the latest 2019 Australian Open odds. Before you make your Djokovic vs. Nadal picks, be sure to check out the 2019 Australian Open predictions from SportsLine tennis insider Sean Calvert.

There are plenty of ways to approach this match, so before you make any Djokovic vs. Nadal picks and tennis predictions, you'll want to see what renowned tennis bettor Sean Calvert has to say, especially given the streak he's on. Not only did Calvert nail the U.S. Open, calling Djokovic -1.5 sets in the final (a straight-set laugher over Juan Martin del Potro), he has also displayed an uncanny feel for the Australian Open. 

Calvert proved it once again in the semis,when he told his followers to back Nadal -6.5 games over Stefanos Tsitsipas. The result: Nadal cruised 6-2, 6-4, 6-0 -- another easy cash.

In 2014, Calvert called Stan Wawrinka's shocking Australian Open championship -- a legendary call that rewarded Calvert's followers with a colossal 60-1 payout. That was the only time in the last 13 years someone not named Federer, Nadal or Djokovic won this event, and Calvert saw it coming. 

Calvert is the same expert who cashed in huge on John Isner at 100-1 to win the Miami Open and just nailed Daniil Medvedev winning the Tokyo Open at 45-1. Anyone who has followed him is way, way up. 

Now, Calvert has broken down the 2019 Australian Open men's singles final and released a highly confident pick on Novak Djokovic vs. Rafael Nadal. He's sharing it only over at SportsLine. 

Calvert knows Djokovic's well-rounded game makes him the current world No. 1. Djokovic took advantage of an inconsistent serving performance in the semifinals from Frenchman Lucas Pouille with his superior return service. Djokovic is widely recognized as one of the best of all-time in that department, which has helped him dominate against Nadal in their careers on outdoor hard courts by a decisive 14-5 margin. 

With many questioning Nadal's conditioning coming out of retirement and the Spaniard serving more aggressively in an effort to avoid long rallies, Djokovic's returns will continue to be critical on Sunday. Calvert also sees Djokovic's backhand as a key to winning his third consecutive Grand Slam title. 

"The Serb's backhand down the line will need to be firing, as that's been one of his great weapons against Nadal, along with the consistency of that wing generally, which has been far harder for Nadal to breakdown over the years," Calvert told SportsLine.

But just because Djokovic is in fine form and on the verge of his third straight Grand Slam championship doesn't mean he'll get the job done against Nadal, who arguably has been even more impressive in the Australian Open 2019. 

Nadal hasn't lost a set all tournament and hasn't been broken since his opening match. "Nadal has been far more aggressive than we've seen him perhaps ever in his career, not willing to engage in many, if any, long rallies, instead hitting his serve far harder, and his backhand too," Calvert told SportsLine. 

"The performance against Stefanos Tsitsipas in the semifinal was superb in its brutality," he added. "Nadal was clubbing winners off the backhand."

Calvert, the unparalleled analyst, has locked in three strong Nadal vs. Djokovic picks. He knows a critical x-factor determines which player has all the value and exactly how long this match lasts. He's only sharing what it is, and what best bets to make, over at SportsLine.

So who wins Djokovic vs. Nadal? And what are the best bets you can make on this riveting 2019 Australian Open final? Visit SportsLine now to see Sean Calvert's top Australian Open championship picks, all from the acclaimed expert who called Stan Wawrinka winning the 2014 Australian Open at 60-1.