Sydney, Jan 2 (IANS): Rafael Nadal's woeful start to the season got a bit more gloomy on Monday as the Spanish World No. 2 suffered his second defeat in the United Cup mixed team tennis tournament.

Nadal, who had earlier lost to Cameron Norrie in Spain's first preliminary round match here, went down to Australia's Alex de Minaur in three games as the hosts took a 1-0 lead in their Group D encounter.

De Minaur came up with a stunning performance here on Monday as he upset Nadal 3-6, 6-1, 7-5 as the 23-year-old rallied from a set-and-a-break down to earn the biggest win of his career by ATP Ranking after two hours and 44 minutes.

"I think it's definitely up there [as one of my best wins]," De Minaur said. "It's one of those achievements that you have unlocked in your career. But also, it's a big win for me, one that I really needed. I'm gonna cherish and use, take all the confidence from this and be able to hopefully take it to have a good Aussie summer.

"It's always a surreal experience playing here. Just walking out there and hearing the support I get on that court is pretty special. No secret [that] it is my favourite court to play on in front of friends and family. I've had so many great memories, and I've been able to add another one to it. I'm extremely stoked," De Minaur was quoted as saying in a report on the ATP Tour's official website.

In a thrilling encounter, De Minaur showed an abundance of grit and quality to delight his raucous home supporters. The World No. 24 scampered around the baseline to hang in rallies, shortening his backswing off his groundstrokes to take away time from Nadal and turn the tables. With his statement victory, the 23-year-old improved to 1-3 in his ATP head-to-head series against Nadal.

De Minaur, who also lost against Briton Cameron Norrie in his opening match of the season, has now earned eight Top 10 wins in his career.

Nadal tasted success on Australian soil last year, winning an ATP 250 title in Melbourne before he lifted his second Australian Open trophy. However, he is still searching for his first win of the new season.

After a slow start at Ken Rosewall Arena, Nadal came to life. He rallied from a break down in the first set, consistently hitting his spots on serve while he pulled De Minaur around the court with his heavy forehand, striking an array of winners to lead.

However, after Nadal gained an early break at the start of the second set, momentum quickly shifted as De Minaur started to time the ball cleanly to force the Spaniard back. The Australian began to find great depth on return, locking down from the baseline to enjoy success on Nadal's serve and level.

With a third set left to decide the clash, it was De Minaur who found a way, gaining the decisive break in the 11th game before holding his nerve to triumph. The 23-year-old let out a roar following his win before he embraced Nadal at the net.

Maddison Inglis will aim to double Australia's lead in the Group D tie when she faces Nuria Parrizas Diaz in the last match of the day in Sydney.

Neither Spain nor Australia can qualify for the City Finals, with both nations falling to Great Britain.