Who is the only man to have won the US Open singles tennis title on three different surfaces (grass, clay, and hardcourt)?
who is the only man to have won the us open singles tennis title on three different surfaces (grass, clay, and hardcourt)
FreebaseQA-train-19118.P0
us open
us open
m.0l6c9
tennis.tennis_tournament.champions..tennis.tennis_tournament_championship.winner
m.01b510
jimmy connors