Strasburg struck out 10, walked one, and allowed three hits in seven innings. Hamels struck out six, walked one, and allowed four hits, all of them singles, in seven innings.
"It's fun any time you get to face one of the best pitchers," Hamels said. "It definitely brings out the best in both of us."
The Phillies entered the day having won eight of Hamels' last 11 starts, including the last three. The 30-year-old lefty has not allowed more than three runs in a start since May 27. In his last 17 starts, he has allowed 24 earned runs with 33 walks, 125 strikeouts and six home runs in 120 2/3 innings. To put that in perspective, heavy NL Cy Young favorite Clayton Kershaw has made 17 starts total this season, allowing 23 earned runs with 150 strikeouts, 15 walks, and six home runs in 121 1/3 innings.
It was the seventh time Hamels finished a start of at least seven innings in under 100 pitches. Only Seattle's Hisashi Iwakuma has more such outings. Manager Ryne Sandberg pinch-hit for Hamels in the top of the eighth as the Phillies searched desperately for some offense on a day when Strasburg shut them down for seven innings.
"It's hard not to think it's a waste of a solid start," said Sandberg, whose team fell to 49-63 on the season, a 70-win pace.
In four starts against Strasburg this season, the Phillies have managed only four earned runs in 25 2/3 innings, with 35 strikeouts and four walks. Washington starters have held the Phillies scoreless for 14 consecutive innings over the last 2 days, with 18 strikeouts and one walk.
"He had real good fastball command, but again, he mixes in his breaking pitches and his changeup real well," Sandberg said. "It's really hard to go up there and just think you are going to get a fastball."
After Hamels left the game, rookie reliever Ken Giles hit the first significant bump in what otherwise has been a spectacular start to his major league career. Giles entered the day having allowed just two runs in 20 2/3 innings, just one of them since the first batter he faced homered. He had held opposing batters to a .171/.216/.257 line with 30 strikeouts and four walks.
Yesterday, however, he retired just one of the five batters he faced, issuing a leadoff walk to Span and back-to-back doubles to Anthony Rendon and Jayson Werth. After an intentional walk to Adam LaRoche, he struck out Ian Desmond for the first out of the inning, then gave way to Jake Diekman, who entered the game to face lefty Bryce Harper. A passed ball and wild pitch during that at-bat allowed Werth to score, pushing the Phillies' deficit to 4-0. Giles was charged with three runs, two of them earned.
"It's just another outing - it didn't go my way," said Giles, who saw his ERA rise to 1.71. "They learned from my previous experiences. I just have to adjust."
To Sandberg, the problem was simple. "He fell behind and left a couple of pitches behind in the count over the plate to a couple of good hitters," the manager said.
The Phillies are off today. Tomorrow they begin a seven-game homestand against the Astros and the Mets. After that, they head to the West Coast for two games against the Angels and three against the Giants.
On Twitter: @ByDavidMurphy