He thought the park's dimensions were just fine afterward.
"I didn't hit one out in batting practice so I was definitely just trying to hit line drives," Crawford said after his third career multihomer game. "I wasn't even thinking about home runs today."
Corcoran (2-0) allowed three hits in his third career start with Tampa Bay.
Washington, reeling after a 1-8 road trip to Boston, Baltimore and Toronto, had its worst loss of the season. The RFK Stadium crowd of 21,854 reserved most of its noise to boo the home team, which lost its fourth straight.
At the midway point, the Nationals are a season-worst 15 games under .500 and in last place in the National League East. Last year, the Nationals were 50-31 and in first place after 81 games.
Second baseman Jose Vidro, who was drafted out of high school by the Montreal Expos in 1992 and remained in the organization through the team's toughest years -- before sparse crowds at Olympic Stadium and in "home" series in Puerto Rico -- said this stretch has been the worst.
"Looking back at the times back at Montreal, and the times here last year I don't remember, this organization, this ballclub being this bad," Vidro said. "It's frustrating. ... In the time that I've been here this is the worst."
Corcoran struck out eight and walked three, and allowed only one Nationals runner to reach third. He has allowed two runs in 15 1/3 innings this year.
Not bad for a minor league journeyman, who was twice selected in the Rule 5 draft and had a 5.96 ERA in 10 major league appearances last year.
"I felt like I could throw it and get outs," Corcoran said. "I felt like I could throw any pitch in there and get an out. I just let the infielders play."
Nationals rookie Michael O'Connor (3-5) struggled in five innings, allowing five runs, eight hits and two home runs in his shortest outing since May 13. Reliever Jason Bergmann followed with two rough innings, giving up six runs and nine hits, including three home runs.
Tampa Bay's Julio Lugo led off the third with a single for his eighth consecutive plate appearance reaching base and Crawford followed with a home run to right field to make it 3-0. In the fifth, Crawford reached on an infield single to lead off the inning, and Baldelli followed with a home run to increase the lead to five.
Crawford and Cantu both hit two-run homers off Bergmann in the sixth. It was Crawford's 12th drive of the season and Cantu's fourth.
"We do have some power but our biggest concern is hitting with runners in scoring position and we did that," manager Joe Maddon said.
Lugo went 3-for-5 and scored two runs and Crawford went 3-for-4 and scored three times.
Ryan Zimmerman singled in Royce Clayton in the eighth for the Nationals.
- Nationals LHP Mike Stanton made the 1,071st appearance of his career, tying him for third on the career list with Hall-of-Famer Dennis Eckersley. Jesse Orosco is first with 1,252, followed by John Franco's 1,119.
- Lugo singled in the first, third and seventh, giving him 17 hits in his last 27 at-bats.
- 3B Aubrey Huff doubled three times, tying a Tampa Bay record achieved six previous times. Huff is 26-for-55 in interleague play; he entered the game with the majors' third-best average in interleague play.
- The Devil Rays' last shutout was June 5 against the Los Angeles Angels.
- Tampa Bay improved to 11-5 in interleague play. The Nationals dropped to 5-11.