Besides her marathon victories in New York and the 1983 World Championships in Helsinki , Waitz also won the London Marathon in 1983 and 1986 ( the latter in a personal best of 2:24:54 ) , as well as the Stockholm Marathon in 1988 at 2:28:24 ( which as of 2011 is still the Stockholm course record for women ) .
Waitz also won the London Marathon in 1983 and 1986 .