Rupp, who won a bronze medal in the marathon at Rio 2016 after winning this event four years ago, turned in a dominant display and won the race by 42 seconds. 

Working under a new coach in Mike Smith after Alberto Salazar was given a four-year suspension last year, Rupp crossed the line in 2 hours 9min 20sec.

The 33-year-old will be competing in his fourth Olympics in Japan, having also won a silver medal in the 10,000 metres in 2012.

Unsponsored runner Jacob Riley was second in 2:10:02, one second ahead of Abdi Abdirahman. 

The pair were narrowly too quick for Leonard Korir to catch and he crossed the line in 2:10:06, an agonising three seconds off an Olympic place.

At 43, Abdirahman will become the oldest runner in American Olympic history when he attends his fifth Games this summer.

In the women's race, Tuliamuk's winning time was 2:27:23, eight seconds ahead of Molly Seidel.

Seidel was running her first marathon. 

Sally Kipyego crossed the line in 2:28:52 to take third place and secure the last Tokyo 2020 berth.

Fourth-placed Des Linden was a further 15 second behind Kipyego, who gave birth to a daughter in 2017 and hadn't shown form this good since.

Kipyego won 10,000m silver for Kenya at London 2012, while Tuliamuk was also born in Kenya.

The marathon will be held in Sapporo this summer after it was moved due to concerns over the heat in Tokyo. 

The women's race is scheduled for August 8, with the men's contest the following day.