Iga Swiatek overcame Spain's Sara Sorribes Tormo 6-2 6-1 at the United Cup on Monday for a second singles win of the season, and partnered Hubert Hurkacz to dish out a "double bagel" that put Poland into the quarter-finals of the mixed team tournament.
Swiatek and Hurkacz eased past Sorribes Tormo and Alejandro Davidovich Fokina 6-0 6-0 in the mixed doubles decider to ensure the top seeds finished as Group A winners in the 18-nation event that offers $10 million in prize money.
"I'm happy right now to have another chef in the bakery," said world number one Swiatek, whose ability to crush singles opponents without conceding games has sparked "Iga's Bakery" memes on social media.
"No, I'm kidding. On Twitter they said the bakery should be closed on New Year's eve, but here we are. I'm happy I played so well and Hubi's a great partner for mixed doubles."
Swiatek, who beat Brazil's Beatriz Haddad Maia on Saturday, earlier dragged Poland back into the tie against Spain with her win over Sorribes Tormo after Davidovich Fokina gave his team the lead with a 3-6 6-3 6-4 victory over Hurkacz.
Casper Ruud also stepped up his preparations for the Jan. 14-28 Australian Open with a pair of wins as he doubled up to guide Norway to a 2-1 victory over Croatia in Sydney.
The former world number two beat Borna Coric 6-4 6-1 to draw his nation level after Donna Vekic defeated Malene Helgo 7-5 3-6 6-3. He then partnered Ulrikke Eikeri to defeat Vekic and Ivan Dodig 6-2 3-6 10-7.
Defending champions the United States could book their spot in the quarter-finals from Group C if they pull off a win over Australia later.
France face Germany in a Group D tie.
Nadal knocked out in French Open first round
Tsitsipas, Swiatek move into French Open second round
Jabeur cruises past wildcard Vickery
Sinner eases past Eubanks at French Open
Asensio misses out as Spain name preliminary Euro 2024 squad
