NEW YORK -- It's only Day 3 of the final Grand Slam of the year, but new records have been set, hearts have been broken and a new extreme heat policy is in place. Simona Halep crashed out in the first round, becoming the first No. 1 seed in the Open era to do so. David Ferrer retired (from the game against Rafael Nadal) for the first time in a Grand Slam on his last ever Grand Slam match. Day 2 got so hot, there were three confirmed retirements due to heat-related circumstances.

On Wednesday, the men's and women's round of 64 will begin and giants such as Nadal, Andy Murray, Serena Williams and Venus Williams will take the stage to get one step closer to the title.

Here's a look at the must-watch matches of the day. Our full airing schedule is here.

Danielle Parhizkaran-USA TODAY Sports

Day session

Two matches to watch

Andy Murray vs. No. 31 Fernando Verdasco: After an encounter lasting three-and-a-half hours with Australia's James Duckworth (and three boxes of sushi after), Murray would want to finish up the next few matches as fast as possible leading up to Week 2, but Spaniard Verdasco poses a big threat to his journey. He has yet to beat Murray since his 2009 five-set victory against the Brit (they've met 14 times with Murray winning 13), but Verdasco will definitely eye his chances considering Murray is not at peak form after making a comeback from a hip injury.

(Watch on ESPN: Noon ET on Arthur Ashe Stadium)

No. 25 Daria Gavrilova vs. Victoria Azarenka: It has been two years since Azarenka played her most recent US Open match. But that didn't stop the two-time finalist from cruising to a first-round victory against Viktória Kužmová. The former world No. 1, who has been involved in a prolonged custody battle in California, will have to dig deep in the second round against No. 25 Gavrilova from Australia. Gavrilova has had a decent year so far, but the highlight of her career is still the victory against Dominica Cibulkova that won her the Connecticut Open in 2017.

(Watch on ESPN+: 11 a.m. ET on Court 17)

Other notables: Defending champion Sloane Stephens will take on 21-year-old Ukranian Anhelina Kalinina on Arthur Ashe, while Venus Williams and Juan Martin del Potro will go up against Italy's Camila Giorgi and America's Denis Kudla, respectively.

Night session

Two matches to watch

No. 1 Rafael Nadal vs. Vasek Pospisil: Nadal will hope to have an easier match when compared to Novak Djovokic at Arthur Ashe. Heat will still play a major role on Day 3, so Nadal will definitely be happy that he won't have to walk out to the court until 7 p.m. He will face Canada's Pospisil of the 2015 Wimbledon fame when he reached the quarterfinals. Nadal should have an easy outing unless something unexpected happens.

(Watch on ESPN2, 7 p.m. ET on Arthur Ashe Stadium)

No. 12 Garbine Muguruza vs. Karolína Muchová: With No. 1 seed Simona Halep out of the way, Muguruza will look to make it to Week 2 of the tournament with thrashing wins in the first few rounds. Her second-round opponent is Czech qualifier Muchova, who beat Ukranian Dayana Yastremska in straight sets in her first-round match. The 22-year-old is playing her first main-draw Grand Slam event this year.

(Watch on ESPN2, second night match on Louis Armstrong)

Other notables: Serena Williams will play Germany's Carina Witthöft at Arthur Ashe and fellow American Jack Sock will take on Georgia's Nikoloz Basilashvili at Armstrong.