The pair, hoping to secure places in the Great Britain team at next year’s Olympic Games, both claimed victories.
Double Commonwealth Games champion Proud set a new personal best and a new championship record in the 50m freestyle.
Proud, swimming for the University of St Mark and St John, clocked 21.40 seconds in the final, having posted a speedy 21.68 in the heats.
He was joined in the final by his Marjon team-mates Aaron Rickhuss and John Slater, who came ninth and 10th respectively with times of 22.78 and 23.14.
James, meanwhile, showed his good form in the 100m butterfly to win by more than one-and-a-half seconds.
Swimming for the University of Plymouth, James stopped the clock in an impressive 51.12 seconds, with Stirling’s former Kelly College pupil Cameron Brodie second in 52.74.
Plymouth’s Perry Gardner reached two individual backstroke finals, while Juliette Casini competed in the 50m freestyle final.
Casini was also part of the Plymouth B team that came second in the 200m freestyle relay. Joining her in that team were Eliza Duffy, Jurate Scerbinskaite and Tami Gonen-Cohen.
Proud is down to swim in the 100m freestyle and 50m freestyle events on Sunday.