LONDON — Gwen Jorgensen and Sarah Groff secured the gold and silver medals at the ITU London stop on Saturday, the first 1-2 finish by American women since the World Triathlon Series was launched in 2009. Jorgensen is now ranked No. 1 in the world, and Groff moves to third.

This is the best finish in London’s Hyde Park for both Jorgensen (St. Paul, Minn.) and Groff (Hanover, N.H.), who competed in the same venue the past three years, including the London 2012 Olympic Games. Jorgensen, who earned her Olympic nomination in London in 2011 with second place, captured the win Saturday in 54:44 on the 750-meter swim, 20-kilometer bike, 5-kilometer run sprint course. This was Jorgensen’s fifth World Triathlon Series title, tying her for the most series wins in history with Emma Moffatt of Australia and Paula Findlay of Canada.

Groff had logged a fourth-place finish at the 2012 Olympic Games in London and held her position on the run to finish second in 55:12. Australia’s Emma Jackson was third in 55:19.