Baseball is rarely a game where greatness is delivered on demand. Yet Nationals phenoms Bryce Harper and Stephen Strasburg were as good as the hype and then some as Washington claimed a dazzling 7-4 victory over the Red Sox.

Strasburg became the youngest visiting pitcher since at least 1918 to record 13 strikeouts in a game, doing so over six innings in which he limited the Red Sox to two runs on four hits and two walks. His 13 strikeouts were the most at Fenway by a pitcher who had not yet turned 24 since Roger Clemens had his record-setting 20-strikeout performance on April 29, 1986.

Strasburg’s fastball lived at 97-98 mph and topped out at 100, complemented by a nasty curveball that he leaned on in the later innings (as his velocity dialed down to 95) and a swing-and-miss 90-91 mph changeup that resulted in some very confused swings.

And then there was 19-year-old Bryce Harper. The teenager had an incredible game, going 3-for-5 with a double, a missile of a two-run homer that cleared the Triangle in right-center and an RBI single, while also making a tremendous catch in left-center and showing off a cannon of a throwing arm. Harper became the first player age 19 or younger to collect three hits in a game as a visitor at Fenway since Ken Griffey Jr. did the deed in 1989; he became the fifth visiting player since at least 1918 to hit a homer at age 19 or younger at Fenway, and the first since Robin Yount in 1975.

Before the game, Red Sox players admitted that from afar, they were in awe of what Harper was accomplishing at such a young age. The opportunity to get a first-hand glimpse only amplified that impression.

WHAT WENT RIGHT FOR THE RED SOX

– Adrian Gonzalez had a great night at the plate, going 2-for-5 with a double (his AL-leading 22nd) and a homer. The homer — a blast to straightaway center against lefty Ross Detwiler — was the 200th of Gonzalez’s career, and his first roundtripper since May 27 (ending a span of 46 at-bats without a homer). In addition to the two extra-base hits, Gonzalez also crushed a ball that was deep enough for a home run to right, but that was instead hauled back in by a leaping Xavier Nady in front of the visitor’s bullpen, close to the 380-foot marker.

– Mike Aviles continued to be one of the Red Sox’ top run producers. With the bases loaded in the bottom of the second inning, he got on top of a 97 mph fastball up in the zone from Strasburg and slammed it off the Green Monster for a two-run double. He’s now hitting .340 with a .903 OPS with runners in scoring position, and his 36 RBI are second to only David Ortiz (37) on the Sox this year.

– After he struck out in each of his first two plate appearances, Dustin Pedroia singled to left to snap an 0-for-14 skid that had encompassed the entirety of his return from a thumb injury.

WHAT WENT WRONG FOR THE RED SOX

– Felix Doubront submitted his worst outing of the year, a performance made all the more puzzling by the fact that he was dominant early. Over four innings (tied for his shortest start of the year), he allowed six runs (a season high) on eight hits while walking two. He struck out six.

He showed a dominant four-pitch mix in the first two innings, in which he struck out four and did not give up a run. But over his next two innings, he permitted all six of his runs on six hits, and his stuff — especially his fastball and curve — remained flat and up in the strike zone, and the Nats teed off on him to the tune of four doubles and a homer.

– Kevin Youkilis went 0-for-3 with three strikeouts, including a looking strikeout on what was arguably the pivotal pitch of the game. Down 7-2 in the bottom of the sixth, the Sox loaded the bases against Strasburg. Youkilis took a 3-2 96 mph fastball that he thought to be low; home-plate ump Doug Eddings disagreed, calling the third strike. Youkilis erupted in dissent and was almost immediately tossed by Eddings for his fourth career ejection. Youkilis has now struck out 37 times in 132 plate appearances this year, a 28.0 percent rate that is easily the worst of his career (his previous high was 21.3 percent in 2009).

– Jarrod Saltalamacchia went 0-for-4 with a pair of strikeouts, including one right before Youkilis with the bases loaded and one out, in which contact would have created the likelihood of at least one run.