Avondale Golf Club's Declan O'Donovan has become the first player to successfully defend the NSW Amateur title in almost 50 years with a resounding win in today's final, while in the Women's, Royal Queensland's Grace Rho claimed the biggest win of her career, taking the crown from a gallant Shyla Singh.

O'Donovan, a two-time NSW representative, claimed the title with a hard-fought 4/2 win over St. Michael's Daley Loumanis in an entertaining contest at Stonecutters Ridge today.

Chasing his little piece of history, O'Donovan cruised through the opening 18 holes to establish a two-hole buffer. He made it three up at the 19th before Loumanis staged a fightback.

With a combination of solid strokeplay and some tentative putting from O'Donovan, Loumanis managed to square the ledger as the pair reached the homeward nine.

The tide was soon to turn in the defending champion's favour, however, and courtesy of a towering drive over the corner bunkers on the par-four 12th to set up a birdie, O'Donovan had his nose in front, and from there, he was not going to let it slip.

A fist pump followed a walk-in birdie on the 14th to get to two up, and when Loumanis horseshoed his birdie putt for a half on the 15th, the match was as good as over. For good measure, O'Donovan rolled in his birdie on the par three 16th to seal his second NSW Amateur Crown.

"It feels incredible," O'Donovan beamed.

"Daley played a great match today and brought every emotion out in me. He got me nervous in the middle stretch there with nine holes to go, but I'm very pleased with myself to finish the way I did."

O'Donovan said he had learned some lessons from his Ford NSW Open appearance alongside LIV stars Cameron Smith and Lucas Herbert last November. The experience, he said, helped him work on improving his game.

"It definitely helped, I went away and tried hard to focus on things and I've come back and it worked."

With his defence, O'Donovan joins a select club of back-to-back winners of the NSW Amateur, which includes Jim Ferrier, Alan Waterson, and the most recent repeat Champion, Colin Kaye, in 1976 and 77.

"I'm excited to go and have a look at the trophy and see who's got two in a row as well that I can compare myself with."

Grace Rho claimed her NSW Amateur in style after a tight battle with her Queensland counterpart Shyla Singh.

The pair couldn't be separated after the morning round, with Singh burying a birdie to square the match on the 18th.

The pair swapped the lead early in the second round, but Rho got her nose in front with birdies on the 23rd, 25th and 28th holes. Singh got one back late.

However, the 18-year-old Royal Queensland representative binned two more birdies on the 31st and 33rd holes to seal the title.

The pair halved the 16th at the end to make the result official, with Rho winning 3/2.

"It feels great," Rho grinned. "My ball striking from day one till today was good. I played some amazing golf."

The win is the biggest for the 18-year-old who has been playing for just six years.

Her name will now sit on the winner's trophy alongside some of the greats in Australian Golf, including Karrie Webb, Nikki Campbell and recent LPGA winner Grace Kim.

"It's an honour to be there with my name among all those professionals. One day, I hope I can be like them as well."