Four-time champion Italy booked a spot in the semifinals of the Billie Jean King Cup Finals with two straight-set victories by Martina Trevisan and Jasmine Paolini on Thursday.

In the Italians' tie against two-time champion Germany, World No.43 Trevisan took down Eva Lys 7-6(6), 6-1, and World No.30 Paolini dismissed Anna-Lena Friedsam 6-3, 6-2. The singles wins gave Italy an insurmountable 2-0 lead.

Italy finished round-robin play at 2-0 and won Group D. Italy had already grabbed a 2-1 victory over three-time champion France on Wednesday.

Italy advances into the final four of the Billie Jean King Cup Finals for the first time since 2014. Italy's most recent title came a decade ago in 2013.

Canada back into semis: Canada joined Italy in the semifinals by besting Poland 2-0 and winning Group C on Thursday. It is Canada's second trip to the semifinals of the Billie Jean King Cup Finals, having also gotten that far in 1988.

Thursday's tie kicked off with a continuation of the breakthrough week by 18-year-old Marina Stakusic. The Canadian teenager, ranked at a career-high No.258, collected her second Top 100 win of the event by outlasting 63rd-ranked Magdalena Frech 4-6, 7-5, 6-3.

Frech led 6-4, 4-2 before Stakusic notched five of the next six games to level affairs at a set apiece. Stakusic surged from there and had double break point for a 5-1 lead in the third set.

However, Frech held firm, getting out of that game, then breaking Stakusic to pull back on serve at 4-3. However, a rally forehand winner down the line gave Stakusic the break back in the very next game, and she served out the match to complete another eye-opening win.

Leylah Fernandez, the 2021 US Open finalist, followed up and clinched the tie by easing past this year's Australian Open semifinalist Magda Linette 6-2, 6-3.

Americans survive Swiss: Later on Thursday, 18-time Billie Jean King Cup champion United States pulled off two singles victories to oust defending champion Switzerland 2-0 in Group A.

In their first tie of the week, the Americans got off to a winning start when Danielle Collins beat 18-year-old Celine Naef 7-6(4), 6-1. Collins was down 4-1 in the first-set tiebreak, but reeled off the next six points, and the second set as well.

The United States' second win of the day was a dramatic thriller, where Sofia Kenin eventually prevailed over Viktorija Golubic 6-3, 6-7(1), 7-5 in 2 hours and 54 minutes.

The 2020 Australian Open champion Kenin had two match points at 6-3, 5-3, but sterling one-handed backhands by former Wimbledon quarterfinalist Golubic kept her in the hunt, and the Swiss squeaked out the second set after dominating the tiebreak.

At 5-4 in the third set, Golubic held a match point of her own, but Kenin triumphed in a lengthy rally to erase that chance, then slammed a forehand winner down the line to hold for 5-5.

Kenin then broke for a 6-5 lead and served for the match again. Kenin saw three more match points slip away as Golubic pulled her from 40-0 to deuce, but the American converted her sixth match point with an error-forcing forehand, clinching the tie and eliminating the Swiss.

The United States will face 11-time champions Czech Republic on Friday, with the winner of that Group A tie advancing to the semifinals.

Australia grabs first winning tie of the week: Also on Thursday, last year's runner-up Australia notched a narrow 2-1 win over Kazakhstan in Group B.

Australia, who fell to Slovenia in the opening tie on Tuesday, has won seven Billie Jean King Cup championships. Their most recent title came nearly 50 years ago in 1974.

Australia and Kazakhstan split Thursday's singles matches. Australia's Storm Hunter beat Anna Danilina 7-6(2), 6-4, and Kazakhstan's Yulia Putintseva bested Kimberly Birrell 6-0, 7-5.

Those results sent the tie to the decisive doubles rubber, where new doubles World No.1 Hunter paired with Ellen Perez to face Danilina and Putintseva. Hunter and Perez, who both competed at the WTA Finals in doubles, dominated the first set 6-1.

However, the Kazakhs rebounded with a 6-4 second set, setting up a match-tiebreak. The Australians saw an early 4-1 lead in the breaker pushed to 5-4, but they won five of the next six points to complete the 6-1, 4-6, [10-5] victory.

The Group B winner will not be determined until after Friday's tie, where Kazakhstan takes on Slovenia.