Four time Olympic gold medallist Mo Farah ran the fastest time of the year to win the 5,000m in the Diamond League meeting in Eugene, Oregon.
The 34-year-old Briton led at the bell and kicked clear to win in 13 minutes 00.70 seconds.
Ethiopian teenager Yomif Kejelcha was second in 13:01.21, with Kenyan Geoffrey Kamworor third in 13:01.35.
Olympic silver medallist Paul Chelimo was seventh in 13:10.11, with GB's Andrew Butchart eighth in 13:11.45.
It was an accomplished final track performance in the US from Farah, who plans to retire from track racing after the World Championships in London this summer.
Having completed a 'double-double' of 5,000m and 10,000m gold at last year's Olympics in Rio, Farah is targeting a fourth successive 5,000m world gold in August.
It was his second competition of the outdoor season following a second-place finish behind American Matthew Centrowitz over 1500m in Los Angeles earlier this month.
Kejelcha, 19, was on the shoulder of Farah coming round the final bend but the Briton pulled away masterfully to secure a comfortable win.
'I've got a target on my back'
Farah was delighted to make an impressive statement to his rivals before the World Championships at Stratford's Olympic Stadium.
"For me it wasn't about time. It was just a matter of telling the boys 'Look, I'm ready'," he said after his victory in Eugene.
"A lot of the boys talk a lot. A lot of guys saying 'I'm going to do this or that.' But I don't like to do that. I just want my running to do the talking and get on with it.
"I've got a target on my back, I've been on the top of my game for the last five years and everyone wants to beat me.
"It's hard trying to maintain it year after year. But I know what I have to do - eat, sleep and train properly. But that's what it takes if you want to win medals."
Farah said he plans to race in Usain Bolt's farewell meeting in Kingston next month before heading to Europe to run in Ostrava.
Second for O'Hare
Also in Eugene on Saturday, Britain's Chris O'Hare was second in the invitational mile.
The 26-year-old Scot clocked 3:53.34, behind Brazil's Thiago Andre (3:51.99), while 16-year-old Jakob Ingebrigtsen of Norway became the youngest sub-four minute miler when he finished 11th in 3:58.07.
In the 100m the top six all ran under 10 seconds but a wind speed of 2.4m/s meant the times were not classed as legal.
American Ronnie Baker won in 9.86, with Britain's Adam Gemili seventh in 10.03.
Andrew Pozzi stumbled at the 10th hurdle and was fifth in the 110m hurdles, Olympic champion Omar McLeod leading a Jamaican one-two, while Matt Hudson-Smith finished seventh in the 400m in 46.08 seconds.
Lynsey Sharp's first 800m of the year brought an eighth-place finish in 2:01.23, South African Caster Semenya winning in 1:57.78.
Laura Muir ran 4:00.47 and was third in the 1500m, which was won by Kenyan Faith Kipyegon in 3:59.67 and Charlie Grice was 10th in the Bowerman Mile in a time of 3:53.62.