Rosindale, 23 from Leeds, overcame a slow start in the swim to get herself up to the front of pack on the bike. Strong running took her to the finishing line ahead of a strong field of U23 women to win her first major title.
She said: “On the bike I just had to really go for it and we caught the main group after about half of the first lap when we got into town.
“I just stayed at the front out of trouble and got into T2, I didn’t have a great T2 but ran out quite hard. I ran out hard and from there I just went to the front and didn’t look back. I just hoped that I’d break Klamer and the Spanish girl.
“With a lap and a half to go I had a gap and just went as hard as I could. It’s amazing!”
Rachel Klamer finished second and Arina Shulgina from Russia was third.
Florin Salvisberg of Switzerland won the men’s U23 race whilst Britain’s Tom Bishop
struggled to repeat the form that saw him win back-to-back races over the last two weekends and finished 21st.
2. Rachel Klamer, NED, 2:06:04
3. Arina Shulgina, RUS, 2:06:12
1. Florin Salvisberg, SUI, 1:49:52
2. Jelle Geens, BEL, 1:50:38
3. Vicente Hernandez, ESP, 1:50:39
21. Thomas Bishop, GBR, 1:54:06
27. David Bishop, GBR, 1:55:02
35. Iestyn Harrett, GBR, 1:55:42
47. Beau Smith, GBR, 1:58:17