Question: At 2006 Dubai Tennis Championships – Men's Singles, Rafael Nadal defeated the defending champion who has won how many Grand Slam singles titles?
Sentence (from "Roger Federer"): Federer has won 19 Grand Slam singles titles, the most in history for a male tennis player and has held the world No. 1 spot in the ATP rankings for a record total of 302 weeks, including a record 237 consecutive weeks.
Relevant evidence: Yes