PHILADELPHIA -- When the Nationals packed up for a nine-game, three-city road trip a week and a half ago, they had won just three of their past 17 games.

Yet, with Sunday's 5-4 win over the Phillies at Citizens Bank Park, the Nats return home having won three straight series.

• Gray to represent Nationals at All-Star Game

Stone Garrett hit his second grand slam of the season as Washington concluded one of its best road trips in years -- one that took the club to both coasts -- by taking two of three from its rival in Philadelphia. That came after winning two of three games in Seattle earlier in the week and doing the same in San Diego last weekend.

“It feels good that the results are paying off for me and for the team,” said Garrett, who also hit the decisive two-run homer in the Nationals’ 2-1 win on Friday night. “Just sticking to the process of getting a good pitch to hit and putting a good swing on it.”

This marks the first time the Nationals have won three consecutive series of any kind since June 14-23, 2021. It's the first time they've won each leg of a three-city road trip since May 29-June 7, 2017 (San Francisco, Oakland and Los Angeles).

“We played hard this whole trip,” manager Dave Martinez said. “Now, let's play a little bit better at home, right? If we play a little better at home, we'll do some good things.”

The fact that Washington's sudden surge came on the road should come as no surprise. After all, the Nats improved to 21-22 away from home this season. But they are just 13-27 at Nationals Park.

So what's been the key to playing nearly .500 ball on the road?

"If I knew the answer to that," Martinez said, "then we'd be playing a lot better at home."

The simple answer is the Nationals are averaging 4.6 runs per game on the road compared to just 3.7 at home. But at the same time, they actually have a higher batting average at home (.266) than on the road (.257). The rest of the peripheral numbers are relatively similar, with their road OPS (.719) checking in just slightly higher than their home OPS (.707).

On the pitching side, the club's 4.59 road ERA is slightly better than its 4.93 home ERA. The key difference there, however, is Washington's starters have a 4.09 road ERA -- nearly a full run better than their 5.08 home ERA.

On Sunday, starter Trevor Williams put the Nats in a hole after allowing two home runs in a three-run first inning. It was an early blow for a club that was already coming off a 19-4 loss on Saturday.

“Proud of the guys in here to not give up, especially after a loss like we had yesterday,” Williams said. “We could have easily put our tail between our legs and just rolled over until we got home. But for the guys to come out today -- especially after giving up three runs in the first -- and continue to fight is huge for us.”

Despite the rocky first inning, Williams did his part by following with four scoreless frames to set the stage for Garrett’s go-ahead slam in the third inning. Jeimer Candelario added a solo shot in the top of the fifth and four Washington relievers combined to allow one run over the final four frames.

"Tremendous series win for us, tremendous road trip for us,” Williams said. “For us to get the win today and go back home on a high note, that's good for us."

Things won’t get any easier for the Nationals upon returning to D.C., where they will close out the first half against a pair of first-place teams. The Nats start the week with four games against the surging Reds before hosting the Rangers next weekend.

"We've got to get home and start playing better at home,” Martinez said. “I don't know the reason for that, because these guys are the same at home as they are on the road. But we definitely have to play better at home.”