Alexander Zverev kickstarted his 2024 season in style Saturday with twin victories at the United Cup in Sydney to spearhead Germany’s defeat of Italy on the first day of play on Ken Rosewall Arena.

After a strong singles win over Lorenzo Sonego in which he did not face a break point, Zverev teamed with Angelique Kerber to win the deciding mixed doubles rubber 6-3, 6-0 over Sonego and Angelica Moratelli.

"We're both extremely happy, the whole team is extremely happy," Zverev said after the mixed win. "Angie played great in mixed and her singles was a high level in her first match back."

Kerber said, "It was a special day for me, coming back after being out for so long and playing at a high level. It feels great to get my first win coming back."

Earlier in the night Zverev levelled the tie with a powerful 6-7(5) 6-3, 6-4 win Sonego, after Jasmine Paolini had given Italy a 1-0 lead after surviving a bout of cramps to defeat Kerber 6-4, 7-5 in the former World No.1's comeback match from maternity leave.

Sonego took the fight to Zverev early, winning 18 of 24 net approaches to edge the two-time Nitto ATP Finals champion in a first-set tie-break. But Sonego couldn’t overcome Zverev’s dominant serving over the course of the match. The 26-year-old didn’t face a break point and won 81 per cent of first serves and 74 per cent of second serves in the two hour, 52-minute battle.

"The first set was one of the best sets I have seen him play, but I just looked for ways to get back into the match," Zverev said. "For the first match of the season I can't complain, and now it's onto the mixed."

Zverev begins the season from a place of strength and confidence, a far cry from his tentative return in 2023, when he was returning from a catastrophic ankle injury suffered at Roland Garros midway through 2022, which ended his season.

Zverev dropped both his matches at the inaugural United Cup and made a second-round exit at the Australian Open. He won just three of his first nine matches of the year but as the season unfolded he recaptured some of his best form and qualified for the year-end Nitto ATP Finals.

Earlier in the evening, Paolini appeared to be cruising at 6-4, 3-1 up, but was forced to recover from 3-4 down after forfeiting two games in order to receive medical treatment in the second set.

Fighting until the last point! 😤

Jasmine Paolini secures Italy's first win after defeating Kerber 6-4 7-5 in Sydney! 💪#UnitedCup pic.twitter.com/GDbc98spfr

— United Cup (@UnitedCupTennis) December 30, 2023

Three-time Grand Slam champion Kerber was competing for the first time since Wimbledon 2022, having given birth to daughter Liana in February. But Paolini, whose improvement from No. 59 to her current career-high of No.30 last season garnered her a nomination for Most Improved Player of 2023, was able to out-hit and out-grit the German over the course of a riveting one hour and 48 minutes.

A nail-biting first set saw at least one break point feature in eight out of 10 games, and incremental momentum shifts meant that it was on a knife’s edge to the very end. Kerber's trademark forehand down the line was on song as she went up 3-1, only for Paolini to reel off four straight games to lead 5-3. The Italian was unable to serve out the set, but came through a brilliant seven-deuce tussle, filled with winners on both sides, to convert her sixth set point in the next game.

Paolini found herself embroiled in another marathon game at 6-4, 3-2 up as she pushed to regain her break lead in the second set. On her sixth break point of the game, she fell to the ground, clutching her left calf. In order to receive medical treatment, Paolini was required to forfeit all the games until the next change of ends, and she returned to court trailing 3-4.

But although Kerber took advantage of Paolini's hampered movement to quickly break for 5-3 and reach set point, the German was no longer playing with her early intensity either. Paolini showed tremendous fortitude in the home stretch, relying on her shotmaking power to rattle off a series of winners — taking her total to 35 — and the last four games of the match.