PERA, SANDGREN, KEYS, DAVIS WIN IN MELBOURNE

As scorching heat sent temperatures into triple digits on Day 4 in Melbourne, it was a pair of lesser-known Americans who remained cool under pressure to continue their journey into uncharted territory.

Bernarda Pera and Tennys Sandgren joined Madison Keys and Lauren Davis in the winners' circle Thursday to advance to the third round of the Australian Open.

Lucky loser Pera (pictured above) kept her fairytale alive with a fine display against 2017 Wimbledon semifinalist Johanna Konta; Sandgren blew past former champion Stan Wawrinka; US Open finalist Keys dropped just one game to Ekaterina Alexandrova; and Davis reeled off a dozen consecutive games to sweep aside Andrea Petkovic.

Pera, who lost in the final round of qualifying last week but was awarded a spot in the main draw when Russia's Margarita Gasparyan pulled out days before the first round, eliminated ninth-seeded Brit Konta in straight sets, 6-4, 7-5.

The 22-year-old is the first lucky loser to reach the third round of the Australian Open since Sandra Kleinova in 1997. She will play No. 20 seed Barbora Strycova in the third round, with the winner set to face either sixth-seeded Karolina Pliskova or No. 29 seed Lucie Safarova in Round 4.

A similar upset was also in the cards in the men's draw, with Sandgren upsetting 2014 Australian Open champion and three-time major winner Stan Wawrinka, 6-2, 6-1, 6-4.

Sandgren will now face Maximilian Marterer for a place in the fourth round against either No. 5 seed Dominic Thiem or No. 26 Adrian Mannarino.

Sandgren, who failed to advance through qualifying at his first 12 Grand Slams between 2009 and 2017, won the USTA French Open Wild Card Challenge to earn a spot in the main draw at Roland Garros in May. In August, Sandgren, then ranked No. 101, earned direct entry into the US Open as an alternate, and he has built on that experience by winning his first and second main-draw matches at Melbourne Park.

The 26-year-old Tennessee native currently sits at No. 97 in the rankings, but he is expected to climb to a new career high around the low- or mid-80s at the end of the month. With a win on Saturday, he could potentially move inside the Top 70 and drastically enhance his chances of directly qualifying for the remaining three Grand Slams of the year.

Elsewhere on Day 4, Keys, the No. 17 seed Down Under, showing no ill effects inside Margaret Court Arena of the wrist problems that limited her to playing just one match since her run in New York in September.

The 22-year-old turned in a dominant display to neutralize Alexandrova and now finds herself in a wide-open second quarter of the draw that has already lost No. 3 seed and two-time major winner Garbiñe Muguruza, 11th-seeded Kristina Mladenovic, No. 14 seed Anastasija Sevastova and No. 28 seed Mirjana Lucic-Baroni.

Keys will next play Romanian Ana Bogdan, who is into the third round of a Grand Slam for the first time in her career.

Rounding out a trio of American women winners Thursday was Davis, a 4-6, 6-0, 6-0 winner over German veteran Petkovic that moves her into the third round of a major for the first time in two years and for just the fourth time overall.

The Ohio native had lost in either the first round or in qualifying in six of the past seven Grand Slams since making the third round in Melbourne to open the 2016 season, and now the world No. 50 will look to climb back toward the Top 32, which she cracked for the first time last spring.

Davis, who also lost the first set of her opening-round match against Jana Cepelova, will play top seed and world No. 1 Simona Halep in the Round of 32 on Saturday.

In first-round men’s doubles action, American Scott Lipsky advanced to the second round with Spain’s David Marrero, and Rajeev Ram was victorious with partner Divij Sharan.

On the women’s side, the all-American team of Jennifer Brady and Vania King won their opening-round match; Madison Brengle booked her place in Round 2 with Puerto Rico’s Monica Puig; and Nicole Melichar moved on with Kveta Peschke.

In other American results Thursday, Denis Kudla pushed No. 5 Thiem to the limit in a grueling 6-7, 3-6, 6-3, 6-2, 6-3 defeat; No. 13 seed Sam Querrey, the last remaining American seed in the men’s draw, fell to Marton Fucsovics of Hungary, 6-4, 7-6, 4-6, 6-2; and Tim Smyczek lost to No. 21 seed Albert Ramos-Vinolas of Spain, 6-4, 6-2, 7-6.

Friday’s action sees Ryan Harrison take on Marin Cilic for a spot in the Round of 16.