This afternoon's charity tennis match has raised more than $65,000 dollars for the Kaikoura rebuild.

Serena and Venus Williams are here ahead of the ASB Classic - and jumped on the court with All Black brothers Julian and Ardie Savea for the charity game.

The four first played an older siblings vs younger siblings match, before swapping to sisters vs brothers.

Caroline Wozniacki later made a surprise arrival on court to join the Savea duo.

Ardie Savea said he was more nervous before the match-up than he ever gets before an All Blacks test, while Venus Williams was complimentary about the brothers' three-day-old tennis skills.

ASB's Mark Graham said while the Saveas' tennis skills weren't quite at the same level as their opponents, it was an entertaining match-up.

He said they had a dance off at certain points, and all the players wore mics so they could talk to each other and give each other a bit of a ribbing on the court.

Mr Graham said they also gave Julian Savea a racket three times the size of a normal one - with which he did surprisingly well.

Graham said all the ticket sales money from the event is being donated to Kaikoura, although it's not clear yet what Kaikoura's mayor will spend the more than $65,000 on.

"They're just working out the best places to put money. You've got probably some people who are in quite important need for some basic things, but then you've also got things like swimming pools with cracks in them, so its just trying to work out where to put that money."