And while all eyes will be on Rafael Nadal, Andy Murray, Victoria Azarenka and Maria Sharapova inside Rod Laver Arena, there are several matchups being overlooked ahead of the Thursday, Jan. 16, action.
Let's take a closer look at a trio of underrated matches tennis fans should keep an eye out for on Day 4.
Christina McHale vs. No. 10 Caroline Wozniacki (8:40 p.m. ET, Jan. 15 on ESPN2)
Former world No. 1 Caroline Wozniacki has exited Melbourne Park earlier and earlier since reaching the semifinals back in 2011. A quarterfinal loss in 2012 and a fourth-round exit in 2013 have her on upset alert on Day 4 against American underdog Christina McHale.
The 21-year-old New Jersey native has had her fair share of early exits at the season's first Slam as well; however, a run to the third round two years ago as a teenager proves the stage isn't too big.
Meanwhile, Wozniacki still has plenty to prove following a poor run of form in 2012 and 2013.
When asked how close she is to reaching her ultimate goal, the 23-year-old Dane paused before delivering a response, per The New York Times' Ben Rothenberg (subscription required):
I don’t know, you know? I feel like I’m on the right track, and I’m doing well. I always work hard, I think I’m a player that’s always giving my all in practice, and I believe that if you work hard, results will come.
Both Wozniacki and McHale won in straight sets in the first round on Day 2, but McHale will need to improve her play on serve in order to spring the upset. Unlike the first round against Yung-Jan Chan, she'll need to win more than 62 percent of her first-serve points in order to stay alive.
McHale's play on return was sensational in her opening match, but Wozniacki was even better, winning 30-of-48 total receiving points against Lourdes Dominguez Lino.
No. 25 Gael Monfils vs. Jack Sock (about midnight ET, Jan. 16 on ESPN2)
Electrifying Frenchman Gael Monfils will look to make it two in a row against unseeded American challengers in Melbourne on Day 4 when he faces off against Jack Sock.
Sock, the world No. 95, has had moderate success on the hard courts at the U.S. Open over the years but is currently in the midst of his first-ever appearance in the Australian Open main draw. Still, don't sleep on the underrated American, who was impressive in his first-round victory over world No. 78 Tobias Kamke.
Sock blasted 16 aces in the four-set win and capitalized on 4-of-10 total break point chances; however, he'll need another fast start if he's going to upend Monfils and set up a potential showdown against men's overall top seed Rafael Nadal in the third round.
And even if Sock isn't up to the task against the No. 25 seed, you won't want to miss an opportunity to see one of the sport's great entertainers—Monfils—play on a rare stage.
No. 24 Andreas Seppi vs. Donald Young (7 p.m. ET, Jan. 15 on Tennis Channel)
Another intriguing second-round matchup featuring an American underdog will pit Donald Young against men's No. 24 seed Andreas Seppi.
This showdown will be the first match featured on Show Court 3 and has the potential to go the distance. After all, Seppi needed five sets to get past Lleyton Hewitt in Round 1.
Meanwhile, Young led Robin Haase in the fourth set of his first-round match before the Dutchman retired.
Keep in mind that Young—who pushed David Ferrer to three sets in New Zealand earlier this year—has never been past the second round at Melbourne Park, while Seppi reached the third round in Australia for the first time in his career in 2013.
Therefore, in addition to the scorching temperatures, both men will be under immense pressure to advance on Thursday.
Follow Bleacher Report Featured Columnist Patrick Clarke on Twitter.