Tom Walsh won the Birmingham leg of the Diamond League shot put in his first competition since becoming the shot put world champion in London two weeks ago, and has set up a mouth-watering showdown at the Diamond League final.

The 25 year old from South Canterbury threw a best of 21.83m in Birmingham to win by 0.28m over American Ryan Crouser.

Crouser hit 21.55m in the first round to grab the lead while Walsh settled into second place with 21.29m in the second round. Crouser had another 21.55 throw in round four, but Walsh took the lead with a big throw of 21.75 in the fifth round.

Crouser could not respond and Walsh extended his lead in the final round with a 21.83 effort to confirm his win.

With a series of 20.75, 21.29, x, 20.92, 21.75. 21.83, the victory confirmed Walsh as the current number one in the world, ahead of Olympic Champion Crouser.

"My biggest worry today was not performing like a world champion," Walsh told NZ Newswire.

"I wanted to prove I deserved to be world champion and I'm pleased that I did that. I got better as the competition went on. To throw that far with a slightly uphill throwing area is very encouraging."

Tomas Stanek from the Czech Republic was third with 21.16m and David Storl fourth with 21.08m.

World champion silver medallist Joe Kovacs was seventh with 20.52m while World champs bronze winner Stipe Zunic from Croatia finished eighth.

Walshs next meeting is a World Challenge meeting in Zagreb, Croatia on August 29.

Heading to the Diamond League shot put final in Brussels on September 1, Crouser has qualified top of the standings on 31 points, with Walsh second on 22 for the eight person final.

The pair will square off at the Brussels meet with the Kiwi World Champion attempting to retain his Diamond League title and the American Olympic Champion trying to wrest it from him.

The winner of the final will win US$ 50,000, the runner will collect US$20,000 and third place US$10,000.

Meanwhile New Zealands other world championship finalist Jacko Gill has had two recent competitions in Europe, finishing third in meetings in Poland and Germany with distances of 20.49 and 20.72 respectively.

- This story has been automatically published using a media release from Athletics New Zealand