Wightman ran a strong final 150 metres to finish ahead of England’s Charlie Grice as he chased home Kenya’s Elijah Manangoi and Timothy Cheruiyot.
Emily Diamond produced a brave run on the final leg for England’s 4x400m team, but was overhauled in the final 50m by Botswana’s 400m champion Amantle Montsho in a duel for third.
In the final race of the day, England’s men’s team saw their title taken by Botswana after an injury to Matthew Hudson-Smith cost them qualification from the heats.
However, the success of England’s 4×100 teams continues a trend set by Great Britain at the Rio 2016 Olympics and London 2017 World Championships.
Despite running a personal best 11.37 in March, anchor-leg runner Ugen – who finished fourth in Thursday’s long jump final – was a surprise inclusion in the team with world silver winners Desiree Henry and Daryll Neita absent.
A powerful start from Asha Philip, a storming back straight from Dina Asher-Smith and expert bend from Bianca Williams, ensured Ugen enough of a cushion to withstand Thompson’s challenge and set a new English record of 42.46 seconds.
“I was told that I had to run so I was like, ‘OK, I can’t disgrace myself,’ said Ugen.
“Bianca gave me the baton and it was, ‘OK, go, go, go.'”