Lyles, Thomas star as USA dominate World Relays
Lyles took the baton from Kyree King and accelerated through the line in 37.40 seconds after slick early handovers by Courtney Lindsey and Kenneth Bednarek.
"Business is easy!" beamed Lyles, who won treble gold at last year's world championships in Budapest. "It smells like Paris!"
Canada took silver in 37.89sec thanks to a late charge by Olympic 200m champion Andre de Grasse.
Reigning Olympic 100m gold medallist Marcell Jacobs ran the second leg for the Italians, the defending world relay and Olympic champions, but was powerless after a devastating first leg by Lindsey gave the Americans a huge gap.
Italy were initially credited with bronze, but were later disqualified, third place instead going to France.
Olympic 200m bronze medallist Thomas then claimed two golds in 20 heady minutes, first as part of the women's 4x100m relay-winning team including Tamari Davis, Celera Barnes and Melissa Jefferson.
They scorched home in a championship record of 41.85sec, with France taking silver in 42.75 and Britain claiming bronze in 42.80.
Thomas was almost immediately back on track, helping a US quartet also comprising Quanera Hayes, Bailey Lear and Alexis Holmes to victory in the women's 4x400m relay in 3:21.70. Poland and Canada rounded out the podium.
"It’s been a great preparation," said Thomas. "At the end of the day I knew the girls would have it regardless because they have a great 4x400m relay squad.
"It's a testament to how we came to World Relays, we came prepared with the mentality to get the job done and we were committed to that."
Bol thwarted
Not to be outdone, the US team of Matthew Boling, Lynna Irby-Jackson, Willington Wright and Kendall Ellis also set a championship record when winning the mixed 4x400m relay in 3:10.73.
Netherlands' Femke Bol, the recently crowned world indoor 400m champion and reigning world 400m hurdles gold medallist, ran a superb last lap of 49.63sec, but the deficit proved just too much and the Dutch had to settle for silver in 3:11.45. Ireland took bronze.
The sole event not to be won by the Americans was the men's 4x400m relay, star Letsile Tebogo running a sensational 43.72sec split to help Botswana to victory in 2:59.11.
South Africa finished second in 3:00.75 with Belgium taking bronze in 3:01.16.
The evening got off to an electrifying start as the Bahamas secured their place in the Olympics by winning their repechage heat in the mixed 4x400m relay in 3:12.81 ahead of Jamaica.
Olympic 400m champions and local heroes Shaunae Miller-Uibo and Steven Gardiner basked in the glory of a raucous carnival atmosphere at the Thomas A.Robinson National Stadium.
"It was a bit rocky but we got it together and qualified for Paris and got a national record," said Gardiner.
Jamaica's women's 4x100m relay team, without world and Olympic gold medallists Shelly-Ann Fraser Pryce, Shericka Jackson and Elaine Thompson-Herah, also secured their place in Paris, having struggled in their opening heat and needing a second bite of the cherry through repechage.
The US men's 4x400m relay squad, the reigning world gold medallists, held it together to safely negotiate their way to Paris through the repechage, though there was heartbreak for the French.
The world silver medallists from Budapest could only finish third in the final repechage heat, meaning no automatic spot for them on home soil.