Preview: Team USA faces Greece as United Cup knockouts begin in Perth

Two compelling United Cup quarterfinals play out Wednesday in Perth as the WTA Tour Driven by Mercedes-Benz continues its opening stretch, with the United States taking on Greece, followed by unbeaten Switzerland facing Argentina.

Let’s break it down:

Perth quarterfinal No. 1: USA (2-0) vs. Greece (2-0)

Taylor Fritz saved a match point Monday against Spain and won a 3-hour, 14-minute match that ended in a tiebreak before Coco Gauff and Christian Harrison sealed the tie in mixed doubles.

Team USA captain Michael Russell was asked how he assessed the dramatic tie.

“The first three hours or the last eight?” he said jokingly. “Look, the team fought so hard like we do. That's why they've done so well here in the past, because everyone is playing for everyone.”

The United States has won two of the three United Cup titles, but the team faces a significant test Wednesday due to a format quirk. As Group A winner, Team USA was meant to play Perth’s best runner-up -- Argentina -- but they already met in group play. So instead, the Americans face Greece, the Group E champion.

Play begins with Gauff taking on a resurgent Maria Sakkari. Their head-to-head is 5-5, but Gauff won both meetings last year in Indian Wells and Miami, each in straight sets.

Stefanos Tsitsipas leads Fritz 3-2 in their ATP Head2Head.

Gauff and Harrison clinched both U.S. wins in mixed doubles.

Sakkari and Tsitsipas -- both looking to reestablish themselves near their peak career rankings -- have guided Greece to the quarterfinals for the third time in four years.

“It’s great that we know that we're at the same position right now,” Sakkari said. “We're trying to get back to where we were.”

Tsitsipas credited Sakkari for helping reignite his belief.

“Maria was the reason I really believed at first,” he said. “She played the breakthrough first. That reignited a new flame inside of me. … I can't help but be proud that we're both in this together.”

Sakkari is already off to a far brighter start than last season’s 20-27 campaign, with strong wins over Naomi Osaka and Emma Raducanu.

Schedule of play

Start Time: 10 a.m. local / 9 p.m. ET

• Women’s singles: Coco Gauff vs. Maria Sakkari

• Men’s singles: Taylor Fritz vs. Stefanos Tsitsipas

• Mixed doubles: Gauff / Christian Harrison vs. Sakkari / Tsitsipas

Perth quarterfinal No. 2: Switzerland (2-0) vs. Argentina (1-1)

A year ago, Belinda Bencic was steadily working back from maternity leave. Today, she’s leading Switzerland again.

“We’re living in Belinda’s world again,” Stan Wawrinka said after Switzerland’s win over Italy. “She’s showing us why we’re here again.”

Bencic is 4–0 across singles and doubles, including the deciding mixed doubles win with Jakub Paul to send Switzerland into the quarterfinals. She opens against Solana Sierra in their first career meeting.

Wawrinka has also been outstanding, producing two long matches including a deciding-set tiebreak win over Arthur Rinderknech. He faces Sebastian Baez.

Argentina’s dominant 3-0 win over Spain -- and their 4-2 overall match record -- pushed them through.

Schedule of play

Start Time: Not before 5 p.m. local / 4 a.m. ET

• Women’s singles: Belinda Bencic vs. Solana Sierra

• Men’s singles: Stan Wawrinka vs. Sebastian Baez

• Mixed doubles: Bencic / Wawrinka vs. Maria Lourdes Carle / Guido Andreozzi

Sydney: Group F: Poland (1-0) vs. Netherlands (0-1)

Poland, last year’s finalist, can clinch the Group F title and a quarterfinal berth against Australia.

World No. 2 Iga Swiatek faces Suzan Lamens at Ken Rosewall Arena.

Swiatek needed two-and-a-half hours to defeat Eva Lys on Monday, improving to 12-2 overall at the United Cup and winning for the 31st time in her past 32 matches against players ranked outside the Top 40.

Lamens, ranked No. 97, pushed Swiatek to three sets at last year’s US Open.

Schedule of play

Start Time: 10:30 a.m. local / 2:30 a.m. ET

• Men’s singles: Hubert Hurkacz vs. Tallon Griekspoor

• Women’s singles: Iga Swiatek vs. Suzan Lamens

• Mixed doubles: Swiatek / Hurkacz vs. Demi Schuurs / Griekspoor

Brisbane International

Another star-packed day as several headliners make their season debuts: No. 2-seeded Amanda Anisimova, No. 4 Jessica Pegula and No. 6 Mirra Andreeva all take the court. No. 8 Clara Tauson also opens play.

In doubles, Aryna Sabalenka and Paula Badosa return as a team in the quarterfinals.

Schedule: Wednesday, Jan. 7

Pat Rafter Arena: starts 11 a.m.

• [WTA] A. Kalinskaya vs. [4] Jessica Pegula

• [ATP] NB 1 p.m.: [1] Daniil Medvedev vs. Frances Tiafoe

• [ATP] [3] Jiri Lehecka vs. Sebastian Korda

• [WTA] NB 6:30 p.m.: [WC] Kimberly Birrell vs. [2] Amanda Anisimova

• [ATP] NB 8:00 p.m.: Doumbia / Reboul vs. Kokkinakis / Kyrgios

Show Court 1: starts 11 a.m.

• [ATP] Alex Michelsen vs. [8] Learner Tien

• [WTA] NB 12:30 p.m.: [WC] Emerson Jones vs. [10] Liudmila Samsonova

• [WTA] Magda Frech vs. [9] Linda Noskova

• [WTA] [6] Mirra Andreeva vs. [Q] Olivia Gadecki

• [ATP] NB 6 p.m.: [LL] Kamil Majchrzak vs. Reilly Opelka

Show Court 2: starts 11 a.m.

• [WTA] [13] Leylah Fernandez vs. Dayana Yastremska

• [WTA] [8] Clara Tauson vs. [Q] Aliaksandra Sasnovich

• [WTA] NB 2:00 p.m.: Paula Badosa / Aryna Sabalenka vs. Cristina Bucsa / Ellen Perez

• [WTA] Hsieh Su-Wei / Jelena Ostapenko vs. [WC] Priscilla Hon / Karolina Muchova

• [WTA] [16] Marta Kostyuk vs. [LL] Yulia Putintseva

ASB Classic

Iva Jovic headlines Wednesday as the 18-year-old American continues her breakthrough week.

Schedule: Wednesday, Jan. 7

Centre Court: starts 11:30 a.m.

• [3] Iva Jovic vs. Sara Bejlek

• [Q] Sinja Kraus vs. Francesca Jones

• Shuko Aoyama / Magda Linette vs. Guo Hanyu / Kristina Mladenovic

• NB 6 p.m.: [7] Wang Xinyu vs. Renata Zarazua

• [Q] Sofia Costoulas vs. [Q] K. Quevedo