Clarke, the 19-year-old sensation fresh off a world junior record equaling 47.85 to claim his first national senior title last month, ran 48.52 to take the win at the Wolfe Track & Field Complex.
Nigerian Nathaniel Ezekiel, who took bronze at the NCAA Championships competing for Baylor University, was not far behind Clarke in second with 48.55 while American David Kendziera ran 48.77 for third.
Watson, the 21-year-old who will be competing at his first World Championships in Budapest, took a big scalp in the 400m with 44.69 to win ahead of Grenadian World and Olympic Champion Kirani James who produced 44.92 in second. American Justin Robinson ran 45.09 in third.
Watson finished second behind Sean Bailey at the Jamaican Championships last month in a personal best 44.54.
Moving over to the 100m where Oblique Seville, who finished third at the National Championships, ran 9.98 for second in the Invitational A-race on Friday.
The race was won by 2022 World Championship silver medallist, Marvin Bracy-Williams of the USA, in 9.96 while Christian Coleman, the 2019 World Champion, was third in 10.03.
BVI’s Rikkoi Brathwaite and Guyana’s Emmanuel Archibald were both top three finishers in the Invitational B-race. Brathwaite ran a personal best 10.09 for second while Archibald ran 10.14, also a personal best, in third. Liberia’s Emmanuel Matadi ran 10.00 to take the win.
Jamaica’s Ashanti Moore and Natalliah Whyte ran 11.18 and 11.26 for first and third, respectively, in the Women’s Invitational B-race. The USA’s Maia McCoy ran 11.24 for second.
Guyana’s Jasmine Abrams ran 11.41 for second in the Women’s Open 100m behind the USA’s Candace Hill (11.29). Kristina Knott of the Philippines was third in 11.47.
Racers Track Club’s Michael Stephens ran 10.28 for second in the Men’s equivalent won by the USA’s Ameer Webb in 10.17. Demarius Smith ran 10.31 in third.
Two-time national champion, Andrew Hudson, ran 20.51 for third in the Men’s Pro 200m. Olympic Champion, Andre DeGrasse, ran 20.19 for a comfortable win ahead of the USA’s Kyree King (20.45).
Jamaica’s Natalliah Whyte ran 22.76 to win the Women’s Open 200m ahead of American Talitha Diggs (22.83) and Nigeria’s Favour Ofili (22.94).
In the Women’s Pro 800m, St. Vincent & the Grenadines’ Shafiqua Maloney ran a personal best 1:59.94, her first time under two minutes, for second behind the USA’s Addy Wiley (1:59.00). Uganda’s Susan Aneno was third in 1:59.95.
The Men’s Pro 800m saw Jamaican national champion, Rajay Hamilton, run 1:46.72 for second behind Kenya’s Festus Lagat (1:46.72). American Abe Alvarado ran 1:46.82 in third.
Dejour Russell ran 13.47 for second in the Men’s Open 110m hurdles. The race was won by the USA’s Michael Dickson in 13.37 while his countryman Dylan Beard ran 13.60 in third.
In the field, Chanice Porter produced 6.67m to take the win in the Women’s long jump ahead of USA’s Tiffany Flynn (6.46m) and Nigeria’s Ruth Usoro (6.42m).
Newly crowned Jamaican champion and national record holder, Rajindra Campbell, threw 21.59m for third in the Men’s shot put behind the American pair of Joe Kovacs (21.72m) and Tripp Piperi (21.67m).
Bermuda’s Jah-Nhai Perinchief produced 16.85m for second in the Men’s triple jump behind American Donald Scott (16.94m). Another American, Chris Bernard, jumped 16.77m for third.