Question: Which tennis player won a major tennis championship in singles, Juan Martín del Potro or Bob Bryan?
Sentence (from "Juan Martín del Potro"): He was the first to defeat both Federer and Nadal during the same major and was the only man outside the Big Four to win a major between the 2005 French Open and the 2013 US Open, a span of 35 tournaments.
Relevant evidence: No