2009 Mutua Madrileña Madrid Open – Men's Singles

Andy Murray was the defending champion, but lost in the quarterfinals to Juan Martín del Potro. Roger Federer won the final against Rafael Nadal, 6–4, 6–4.

The semifinal match between Rafael Nadal and Novak Djokovic was at the time the longest men’s tennis match in the Open era played with the best-of-three system, stretching for 4 hours and 3 minutes with Nadal prevailing, 3–6, 7–6^(7–5), 7–6^(11–9). This record was later broken by Roger Federer and Juan Martin del Potro at the 2012 London Olympics in their 4-hour and 26 minute semifinal match.