WASHINGTON -- For five innings on Wednesday at Nationals Park, Washington went toe-to-toe with an expected American League East contender and its staff ace.

Then it all came apart, serving as an early reminder of how thin the margins will be this season for a rebuilding, youthful ballclub in a 7-2 loss to the Rays.

“Just a learning experience for a lot of guys here,” said Nationals starter Patrick Corbin, who pitched better than his line of six runs in six innings suggested. “Losing is not fun. No one wants to lose. But the good thing is, we play again tomorrow. A lot of times you have to have a short memory. Come to the field and work and try to get better, try to learn and move on.”

There were promising performances. Victor Robles continued his strong start with two hits and a walk. Stone Garrett singled and walked twice in his Nationals debut. And Corbin at times showed echoes of his younger self, the left-hander who posted a sub-4.00 ERA with 30 or more starts three times between 2013 and ‘19.

But there were two key frames that tilted the game in the Rays’ favor.

First, Rays lefty Shane McClanahan escaped a bases-loaded, none-out jam without allowing another run in the bottom of the fourth to keep his team holding a narrow 3-2 lead.

Then, Corbin yielded three sixth-inning runs -- allowing four consecutive hits after retiring 11 batters in a row -- with a difficult sun playing a key role.

And when the smoke cleared, the Rays (6-0) remained MLB’s only unbeaten team, while the Nationals were swept by Tampa Bay for the first time since 2006 and the first time ever in Washington.

“We’re going to get better, there’s no doubt about that,” Nationals manager Dave Martinez said of his 1-5 ballclub. “And we’ve got just a lot of baseball left. … I want to win every day, believe me. But I’m not going to put any onus on the first week of the season. I’m not.”

The outcome soured a reasonably mature offensive performance against McClanahan, who finished fifth in the AL with a 2.54 ERA last season despite pitching in a division known for offense.

The Nationals put nine runners aboard with five hits and four walks against McClanahan, and they snapped his scoreless start to 2023 in the second inning on Robles’ RBI double.

But then came the missed opportunity in the fourth, after Joey Meneses doubled and scored on the first of four straight Washington hits to open the frame.

With the bases loaded, McClanahan did what aces often do -- inducing Robles into a flyout to shallow right that failed to advance any runners, then striking out CJ Abrams and Lane Thomas on six total pitches.

Abrams struck out swinging on a fastball just above the zone at 99.6 mph, per Statcast. Thomas also chased a third strike on another heater that clocked in at 100.3, the second time McClanahan hit triple digits on the afternoon.

“We were trying to get him in the strike zone. We accepted our walks early. We hit some balls hard,” Martinez said. “I thought we handled our at-bats well until that moment.”

Corbin recovered from a bumpy beginning to cruise through the fourth and fifth innings, and he looked like he’d do so again in the sixth after Robles made a fine diving catch in center to retire Isaac Paredes for the first out.

But with two out, Harold Ramírez drove a 1-1 slider narrowly over the center-field wall to make it 4-2. Manuel Margot followed with a single, and he scored when Robles lost Taylor Walls’ fly ball to center in the sun as it dropped to his right for an element-induced double.

Walls scored on Jose Siri’s single to cap the three-run inning before Siri ran into an out on the basepaths.

“Sometimes the ball goes in there and gets lost in there,” Robles said via a translator of trying to track Walls’ double through the sunshine. “All I can do is try to fight it, and hopefully you see it when it comes out of there. But sometimes you can’t, and that’s all I can do.”