Portugal Colonial - Gauff, Paolini on fire as USA, Italy surge into United Cup quarters

World number three Gauff swept past Croatia's Donna Vekic 6-4, 6-2 to avenge a loss at the Paris Olympics, while Fritz took care of Borna Coric 6-3, 6-2 in searing Perth heat.

That was enough to put the Americans -- the 2023 winners -- into a last-eight clash with China.

Elena Rybakina's Kazakhstan meet defending champions Germany, led by Alexander Zverev, in the other Perth quarter-final.

In Sydney, the in-form fourth-ranked Paolini demolished France's Chloe Paquet 6-0, 6-2 to help steer an Italian team missing Jannik Sinner into the knockout round with their opponent yet to be decided.

Iga Swiatek's Poland play the Czech Republic on Wednesday in a bid to join them, while Britain take on Australia.

World number four Fritz got the ball rolling for the US, adapting his game to Coric's approach.

"At the start he was hitting well and staying with me from the baseline. It was tough to hurt him," he said. "But I tried to make fewer mistakes and let him make a couple -- that was the difference."

"It was just great to get the win, good to get it done."

Gauff put the tie beyond Croatia's reach against Vekic, who scored an upset win against her on the way to a silver medal at the Olympics.

"That defeat really hurt, but it was really just motivation to do better," said Gauff, who won eight of the last 11 games.

"I'm happy how I served and competed today throughout the entire match.

"We're through to the quarter-finals -- let's go."

Paolini had a memorable 2024, finishing runner-up at Roland Garros and Wimbledon and winning her second career title in Dubai.

She also triumphed with Italy in doubles at the Paris Olympics and helped her country to Billie Jean King Cup glory, bringing that form to Australia.

- High level -

After thrashing Belinda Bencic 6-1, 6-1 in her season-opening match, she showed Paquet no mercy in a warning shot heading into the Australian Open.

"I played a really solid match. I was happy with my performance and focused all the time," she said.

"Everything worked pretty well. Not too many mistakes and my level was high."

Paolini won the first seven games before Paquet got on the scoreboard. But it was a minor blip with the Italian quickly taking charge again with a flurry of winning volleys to claim victory.

Her teammate Flavio Cobolli put Italy 1-0 ahead with a battling 3-6, 7-6 (10/8), 6-2 upset of French world number 14 Ugo Humbert.

It was the second consecutive win of the season for the 22-year-old, who has been steadily climbing the rankings in recent years to his current world number 32.

"It was a great battle to start the season, so I'm really happy about the match," said Cobolli, who saved a match point in the second set.

Humbert served for the match at 6-3, 5-4, but Cobolli recovered to take it to a tiebreak and saved match point at 8-7 before rallying in the third set for the win.

P.Cavaco--PC