Denis Istomin

Harrison beats Hewitt in first round of Citi Open

Just 21, Ryan Harrison has a pretty mature understanding of what it takes to make it on the ATP tour.

"You've got to love the process," Harrison said after his 6-3, 7-5 win over former world No. 1 Lleyton Hewitt on Tuesday in a first-round Citi Open match at William H.G. FitzGerald Tennis Center. "No matter how tense any moment can get out there, it's what we live for, it's what we play for."

That mantra will be worth recalling today, when he will meet top-seeded Juan Martin Del Potro, a Wimbledon semifinalist and two-time Citi Open champion, in the second round. Del Potro won't be taking him lightly.

"He has a very good game, he serves very...