del Potro Into Citi Open Quarterfinals After Wins Over Tomic and Harrison
Juan Martin del Potro advanced to the 2013 Citi Open quarterfinals in Washington, D.C. on Thursday after winning twice over the course of seven-and-a-half-hours. He first defeated 107th-ranked Ryan Harrison 6-1, 7-5, and then beat 14th-seeded Bernard Tomic 6-3, 6-3. They played for about 70 minutes in each match. Harrison was trailing 4-0 after only…

