Sentence:  Since riding Harry Payne Whitney's Whiskery to victory in the Kentucky Derby, Jockey Linus ("Pony") McAtee has twice broken into the news in unconventional fashion. A fortnight ago, he won a <WSD>one-horse race</WSD> ("walkover") at Belmont Park, N. Y. 
Meaning of the word marked with <WSD> tags:  A horse race in which a single horse takes such a considerable lead that the other horses are no longer contenders to win.