SYDNEY, Australia  -- World No.3 Jessica Pegula tallied her first win of the season with a 6-3, 6-2 win over Germany's Laura Siegemund on Day 6 of the United Cup. After wins from Taylor Fritz and Madison Keys on Day 5, Pegula's victory delivered the favored Americans an insurmountable 3-0 lead over Germany.

With a win against the Czech Republic in their opening tie, the U.S. will finish Group C undefeated and advance to the City Finals where it will face Great Britain.

Tuesday's victory was a meaningful one for Pegula in more ways than one. The win was her first singles win since capturing the biggest title of her career the Guadalajara Akron Open in October, snapping a four-match losing streak that began at the WTA Finals. 

Coming off a hotly contested 7-6(6), 6-4 loss to Petra Kvitova in her first match of the season, Pegula put in a comprehensive and dominant baseline performance to defeat Siegemund. The German struggled to gain any traction in Pegula's quick service games, with Pegula winning 75% if her first-serve points and 79% of her second-serve points. The American lost just 10 points on her serve. 

"I thought the conditions were playing very fast, so I just tried my best to play quick 1-2 tennis, serving well, first ball being aggressive," Pegula said. "I thought I did that well."

With the tie secured, Frances Tiafoe played with freedom and confidence when he beat Otte to further extend his nation's advantage to 4-0. 

In his first ATP Head2Head meeting against Otte, the 24-year-old was strong on serve, firing nine aces and winning 97%  (29/30) of points behind his first delivery to triumph after 77 minutes.

Tiafoe has now earned two wins this season. The American held a 35-25 record in 2022, reaching tour-level finals Estoril and Tokyo and the last four at the US Open.

Pegula and Tiafoe teamed up to complete the clean sweep for the Americans, defeating Laura Siegemund and Daniel Altmeier 6-7(5), 6-4, 10-7 in the mixed doubles. 

Looking ahead to Wednesday's City Finals against Great Britain, Pegula will prepare to face Harriet Dart in singles. The winner of the City Finals will advance to the United Cup Final Four, which begins Friday. 

The ATP Tour contributed to this report.