Olympic champion javelinist Neeraj Chopra fell short at the Doha Diamond League on Friday as America's Kenny Bednarek scorched to a world-leading 19.67sec 200 metres as the Paris Olympics looms.

Chopra's final throw of 88.36m was just two centimetres behind his Czech rival Jakub Vadlejch, who took silver behind the Indian at the Tokyo 2020 Games.

Elsewhere, Tokyo 2020 gold medallist Steven Gardiner said he was "just where I wanted to be" after a dominant 400m win at Qatar Sports Club Stadium, 11 weeks before the Paris Games.

And Kenyan world title-holder Mary Moraa held off Britain's Jemma Reekie to win the women's 800m by half a second in 1:57.91, her season's best.

After Doha, there are seven more Diamond League meets around the world -- including Paris on July 7 -- before the Olympics start on July 26.

In the javelin, Vadlejch hurled 88.38 with his third throw, with Chopra unable to surpass him in his first competition of the season.

"It was a little bit revenge for last year," said Vadlejch, who lost out to Chopra by four centimetres in Doha last year.

"I think it's a good rivalry and it's good for the spectators."

Chopra, who again missed out on joining the elite 90m club, vowed to improve next time around.

"I'm satisfied with the result but I'm not satisfied with my effort," he said. "I think I can do something about this and maybe next competition I will throw far."

- Bednarek 'ready to go' -

Bednarek, second to Canada's Andre De Grasse at Tokyo 2020, laid down a marker for next month's US trials with his 19.67, his personal best and a meet record, against a strong 200m field.

The 25-year-old beat his victorious 4x100m World Relays team-mates Courtney Lindsey and Kyree King into second and third place, with Joseph Fahnbulleh completing an American one, two, three and four.

"I feel great about the race. I knew I was in this shape, I just had to put it down on the track," Bednarek told AFP.

"I'm healthy, I'm stronger than ever and I'm ready to go."

Meanwhile Gardiner, of the Bahamas, ran 44.76 to win the 400m ahead of Zambia's Muzala Samukonga, with Tokyo 2020 relay gold medallist Vernon Norwood of USA fourth.

"It's put me in a good position," Gardiner said afterwards.

"My health has to come first but it's just where I wanted to be -- just have a healthy season this year and come out on top in Paris."

Kenya's Moraa, crowned 800m world champion last year in Budapest, was pushed all the way by Reekie, the world indoor silver medallist.

"I can say it was a hard race, all of us were in good shape," said Moraa.

In the men's long jump, Greek Olympic champion Miltiadis Tentoglou's 8.36 was only good for second behind Jamaican Carey McLeod's monster leap of 8.52.

"It was my first competition and I was feeling kind of rusty at the beginning. But every time I was getting better," said Tentoglou.

Brazil's Alison dos Santos set a meet-record 46.86 in the men's 400m hurdles -- the fifth fastest time ever.

And Britain's Daryll Neita pipped America's Tamari Davis on the line to win the women's 100m by one-hundredth of a second in 10.98.

Kenya's Brian Komen came out narrowly ahead of compatriots Timothy Cheruiyot -- the former world champion and Tokyo 2020 silver-medallist -- and Reynold Kipkorir Cheruiyot with 3:32.43 in the men's 1,500m.

In the women's pole vault, Britain's world indoor champion Molly Caudery won on countback against reigning world champion Nina Kennedy of Australia after they both cleared 4.73.