The US team featured two of the individual 100m finalists, Fred Kerley and Ronnie Baker, the world leader Trayvon Bromell, and Cravon Gillespie, who also ran the heats en route to their 2019 world championship title.

But despite the depth of talent on show, a shocking second changeover saw them lose all momentum and Gillespie was unable to run them back into contention in a mass finish, with China the surprise heat winners in 37.92 in Tokyo on Thursday.

Canada were second, two thousandths of a second behind, and Italy, helped by newly-crowned individual champion Lamont Marcell Jacobs, posted a national record 37.95 to also advance.

Jamaica led the way in the other semi, qualifying fastest in 37.82, ahead of Britain (38.02) and Japan (38.16)

After dominating the event for decades, a succession of disqualifications contributed to the US not managing gold since 2000 and this is the latest setback in what has been a below-par performance in Tokyo for the male side of the sport's traditionally most powerful nation.

It is 10th time since 1995 that the men have botched a relay at a world championships or Olympics. They were disqualified for a faulty exchange five years ago in Rio de Janeiro.

Lewis, who helped the US to two Olympic and three world sprint relay golds, was one of many to take to social media to share his disappointment.

"The USA team did everything wrong in the men's relay," Lewis tweeted.

"The passing system is wrong, athletes running the wrong legs, and it was clear that there was no leadership. It was a total embarrassment, and completely unacceptable for a USA team to look worse than the AAU (American Association of Universities) kids I saw."

In the women's 4x100 relay heats, Dina Asher-Smith recovered from her hamstring strain to help Britain to a national record of 41.55 seconds and into the final as the fastest qualifiers.

Asher-Smith withdrew from the 200m, where she is world champion, after being hampered by the injury in the 100, but she showed no ill-effects while running a superb third leg as Britain won their heat from double defending champions the United States.

The US (41.90) and Jamaica, who finished third in 42.15 but will probably be strengthened by the introduction of Elaine Thompson-Herah and Shelly-Ann Fraser-Pryce, also advanced to Friday's final.

Gina Luckenkemper ran a storming last leg as Germany overhauled Switzerland to win the second semi in 42.00 while the Swiss notched a national record -- one of five on Thursday -- of 42.05 and progress as the fourth-fastest qualifiers.

with The AP

Australian Associated Press