Shane Watson scored an unbeaten 105 yesterday to guide Australia to a six-wicket victory over New Zealand and back-to-back Champions Trophy titles.

Chasing New Zealand's 200 for nine, Australia struggled early with the loss of Tim Paine and Ricky Ponting with just six runs on the board. But opener Watson and Cameron White (62) put on 128 for the third wicket to set up yesterday's win. Australia reached 206-4 in the 46th over.

"We needed discipline at the start," said Watson, who posted an unbeaten 136 in Australia's semi-final win over England. "It was hard to score and even to survive in the beginning."

Once Watson settled in, New Zealand's hopes slowly evaporated.

"I knew if I could be around in the 40th over, we'd have a chance of winning," Watson said.

The Australians beat the English by nine wickets in the semis and were hot favourites to become the first team to retain the Champions Trophy title.

"We've been bringing younger, fresher faces into the side," captain Ricky Ponting said, "and two of them saw us home tonight, and they handled the situation very well."

Top scorer

New Zealand struggled to 200-9 in their 50 overs, having won the toss and elected to bat.

The Black Caps lost stand-in captain Brendon McCullum early for a duck in the fourth over after making a slow start. McCullum was deputising for Daniel Vettori, who injured a hamstring in the morning while the teams were preparing for the match.

Martin Guptill was the top scorer for New Zealand with 40 off 64 balls, while the middle-order pair of Neil Broom and James Franklin shared a partnership of 65 for the sixth wicket in just over 14 overs.

Spinner Nathan Hauritz kept things quiet for Australia in the middle overs of the innings and finished with 3-37 off his 10 overs. Paceman Brett Lee returned 2-45.

"Kyle Mills and Shane Bond were brilliant today," McCullum said. "It was a fantastic effort from them, but in the end we didn't have enough runs on the board."

He added: "We came together as a group throughout the tournament," said McCullum, "and we had huge expectations going into the final. But Australia were brilliant today and they are deserved winners of the trophy."