Two weeks ago, when the young Phillies rode a winning streak to the West Coast, they spoke inside the clubhouse of the upcoming test that awaited them. The 10 games against three of the league's prohibitive favorites - Los Angeles, Chicago, and Washington - in 10 days served as a virtual measuring stick.

The Phillies owned a lead in nine of those 10 games, including Sunday's 6-5 comeback win over the Nationals. They have won just twice in their last 10, the sort of stretch that can wound a team.

"We went through that last year," Phillies manager Pete Mackanin said. "We were playing in so many close games. The pitching really held us together last year. Not so much this year. But we're doing the same thing this year. We're on the verge of becoming a better team."

The manager believed that even before Aaron Altherr launched a game-tying three-run homer in the eighth inning. But that blast served as some affirmation.

While it may not materialize in the immediate standings, these Phillies have improved. They are not in the class of the Dodgers, Cubs, and Nationals, but they are at least close enough to compete. They were outscored by just nine runs in the 10-game challenge, a number that reflects how most of the defeats were narrow.

For a rebuilding team, that can signal some progress.

"To get this win was huge," Altherr said. "Hopefully we can ride this and win more games."

"You have to admit," Mackanin said, "after losing five in a row, these guys were very resilient."

They were silenced for most of the chilled afternoon. Altherr's pinch-hit swing tied it after an afternoon of limited chances to score. The Phillies won it in the 10th on Freddy Galvis' sacrifice fly.

Odubel Herrera started the inning with a check-swing double. Altherr was intentionally walked. Vince Velasquez, asked to pinch-hit and bunt, dropped a perfect one in front of the mound that caused Nationals pitcher Blake Treinen to collide with his catcher, Jose Lobaton. Then Galvis delivered.

Altherr has emerged as one of the more intriguing figures on this Phillies team. He did not start Saturday or Sunday because of a sore left wrist injured while diving for a catch Friday night. His presence was missed.

He walked to the plate Sunday with two outs in the eighth inning. Washington manager Dusty Baker opted for veteran righthander Matt Albers to face Altherr.

The 26-year-old outfielder attacked a first-pitch slider. It landed 412 feet away, in the center-field stands.

"I'm looking forward to watching him play a little bit more," Mackanin said.

It was Altherr's 11th extra-base hit in his 74th plate appearance this season. He managed just 10 extra-base hits in 227 plate appearances in 2016, a sign that a significant wrist injury affected him until the end of the season. Now Altherr's spot in the Phillies lineup is guaranteed.

The Phillies have played 30 games this season. Nine have come against Washington, the team with the best record and the highest-scoring offense in baseball. The Nationals played this entire weekend without their best hitter, Bryce Harper, who sat out with a groin injury. They rested Ryan Zimmerman and his red-hot swing Sunday.

Still, the gap between these two franchises appears closer than in previous seasons. Washington has dropped 10 games in 2017. Four of those losses are to the Phillies. Washington's deep lineup of skilled hitters can overwhelm for three days, with mounds of evidence as to why this could be the Nationals' season. Their haphazard bullpen operates counter to that.

The Phillies were hitless until the fourth. Jayson Werth, this ballpark's villain, crushed two homers in the game's first five innings. Jeremy Hellickson could not complete five innings. The deficit widened with a wild Jake Thompson on the mound.

But, after 3 hours, 51 minutes of baseball, none of that mattered because Altherr rescued his teammates.