Sri Lanka spin king Muttiah Muralidaran admits he has introduced changes into his game to keep batsmen under his spell.

Muralitharan took 4-31 as Sri Lanka beat New Zealand by 81 runs on Tuesday to lead the 1996 champions into Saturday's ICC CWC final where they will face Australia.

"I'm bowling really well around the wicket a lot at the moment and that's a new tactic that can help me," said the 31-year-old.

"It seems that when you can't see which way the ball is going it's harder. So hopefully that helps me in the future and I'll take more wickets.

"People are getting ready for the spin, so if I bowl the 'doosra' I might get a top edge."

Muralidaran, one of the survivors of the 1996 title-winning team, took his toll for the 2007 tournament to 23, bettered only by Australia's Glenn McGrath, and his overall ODI career record to 455.

He said he was looking forward to the final which takes place at Bridgetown on Saturday.

"We'll need to do different things well. So we'll wait and see who is in the final and hopefully we'll be ready for them."

Sri Lanka captain Mahela Jayawardene, who was man-of-the-match for his unbeaten century, hailed the spinner.

"He is always trying to take wickets and keeps the pressure on," said Jayawardene.

"He was one of the unsung heroes. He changed the game at a crucial part of the match."