On Monday, Merewether's Lancaster finished with scores of 6.0 and 8.23 for a two-wave 14.23 total to defeat Ben Zanatta (12.5), Chex Dempsey (6.96) and Lachlan Arghyros (1.4) in the under-14 final at Maroubra.

Byrnes and Thomas won the under-16 and 18 crowns respectively a week earlier in Illawarra. Newcastle East End Boardriders Club surfer Thomas backed up a dominant run to his final with an early 9.9 wave before a score of 5.45 and 15.33 total to beat Harley Walters (11.23), Harry O'Brien (8.4) and Hughie Vaughan (8.16).

Merewether Surfboard Club 13-year-old Byrnes also made a flying start in his final with opening scores of 6.5, 7.1 and 7.07 for a 14.17 total to beat Sol Gruendling (13.43), Dayan Conti (6.49) and Kash Brown (5.47). It was a first NSW title for good mates Byrnes and Lancaster.

Byrnes was seeded to start in round three, which he won with a 13.1 total, but from there he did it the hard way, finishing second in his round four and quarter and semi-finals heats to make the decider.

Lancaster, also 13, has won the Oz Grom Cup, Under 12 Grom Search national finals, Sandbah Cup and the Newcastle regional titles this year.

"I'm frothing," Lancaster told Surfing NSW.

"The waves have been on and everyone's been ripping. This is my first win, I've been close a couple of times and it's been great to be surfing with my mate Ben [Zanatta] especially out here in these conditions."

The winning trio will now be invited to high performance camps in the lead-up to the national junior titles, which are set down for November 26 to December 3.

MORE IN SPORT:

Our journalists work hard to provide local, up-to-date news to the community. This is how you can continue to access our trusted content: