It's been more than a month since Henderson Alvarez last won a game for the Toronto Blue Jays. Despite the ever-lengthening drought, Alvarez doesn't see any reason to panic.

Bryce Harper homered off the restaurant in center field, Danny Espinosa added a two-run blast and the Washington Nationals beat the Blue Jays 4-2 Tuesday night, extending their winning streak to five games.

Jhonatan Solano added his first career homer as the Nationals improved to 6-2 in interleague play.

All three homers came off Alvarez (3-6), matching his season high. He hasn't won since May 10, a span of six starts.

"I don't feel bad about that," Alvarez said through a translator. "I feel like I'm throwing the ball well and I'm going to continue to pitch. (Wins) will come."

Blue Jays manager John Farrell said Alvarez's struggles are compounded by "inconsistency" with his key pitch, the sinker.

"Particularly to left-handers, it's got more of a riding action and lateral movement rather than the downward sink that we've normally seen from him," Farrell said. "If he's up in the zone a little bit without that late hard sinking action, we've seen what's taking place."

Alvarez allowed four runs and nine hits in seven innings. He walked none and struck out three. The second-year righty is 0-4 with a 5.50 ERA in his past six starts, all Blue Jays losses.

"When he's missed on the plate, he hasn't gotten away with a mistake," Farrell said.

Jose Bautista hit a two-run shot, but the Blue Jays lost for the fifth time in six games and dropped to .500 at 31-31. Toronto has not been below .500 at any point this season.

Harper's blast was the biggest of the three off Alvarez. His seventh career homer was a two-out rocket that smacked off the windows of the restaurant in center. The impressive drive left many in the crowd of 22,538 gasping at the teenage rookie's raw power.

"That was a changeup right in his wheel house and he didn't miss it," Johnson said. "I don't know why the outfielder went back. It was obviously a long way out of here."

Harper posted his second straight three-hit game, finishing 3 for 4. He singled in the first, homered in the third, grounded into a fielder's choice in the fifth and reached on a bunt single in the eighth. Harper has reached safely in eight of his past 10 plate appearances.

"I don't really hit big home runs," Harper said. "It's usually just line drives that get going. That was a pretty good one tonight."

With ace Stephen Strasburg facing Toronto's Kyle Drabek in Wednesday's series finale, the Nationals have a chance to finish off the first 6-0 road trip in team history.

(Wednesday) is going to be a big day," Nationals manager Davey Johnson said. "We've got our big horse going. We just need to finish this off."

Washington's five-game winning streak matches a season best. The Nationals also won five straight from April 10-14.

The win, coupled with Atlanta's home loss to the New York Yankees, gives Washington a four game lead atop the NL East standings.

Chien-Ming Wang earned his first victory as a starter this season in his third attempt, allowing two runs and four hits in five innings. Wang (2-2) walked five and struck out five.

Ross Detwiler worked 1 2-3 innings, Craig Stammen got one out, Sean Burnett worked the eighth and Tyler Clippard finished in the ninth for his ninth save in 10 opportunities.

The Blue Jays used a hit batter, a single and a walk to load the bases with two outs in the bottom half, but Wang caught Edwin Encarnacion looking to end the threat.

"We're scuffling right now a little bit with men in scoring position," Farrell said.

Washington got another two-out homer in the fourth, with Espinosa hitting a two-run shot to center, his sixth.

Bautista brought the Blue Jays to within one in the fifth with a two-run shot to left, his 18th. Bautista has homered three times in his past five games.

Solano made it 4-2 with a two-out solo homer to left in the seventh on a 0-2 pitch.

NOTES: Tests on Toronto RHP Brandon Morrow, who left Monday's start after just nine pitches, confirmed the initial diagnosis of a strained left oblique. Morrow will be placed on the 15-day DL Wednesday. ... The Blue Jays granted OF Vladimir Guerrero his release. Guerrero, who signed a minor league contract last month, had been playing at Triple-A Las Vegas. ... Toronto sent INF Yan Gomes to Triple-A. ... An MRI on Washington OF Roger Bernadina's sore right hamstring revealed no damage. Bernadina will be given two or three days off, Johnson said. ... Toronto OF Ben Francisco (left hamstring) began a rehab assignment with Class-A Dunedin Tuesday, going 0 for 2 with a walk.