Clement took almost six seconds off his previous PB with a time of 2:38.67, while Feinson improved hers to 3:08.16.
Their coach, Steve Norris, said: “Jacob settled down early on, paced his race well and finished strongly. Everything he had done in training came together.
“But heavy traffic on the way to Lee Valley meant Daisy unfortunately had to miss her seeded race. She was put in with a mixed group of other late arrivals instead, and the race went off faster than she expected.
“She dealt well with those tricky circumstances, and it was a useful learning experience for her. Both Daisy and Jacob worked hard throughout the winter on pacing and race tactics, including during the holidays, and I can see that it is all starting to pay off.”