WASHINGTON -- The Nationals again were unable to hold the Dodgers at bay early in a 7-3 rain-delayed loss in the series finale at Nationals Park on Sunday.

Contributing to Washington’s recent slide has been an inability to pitch well to begin games. The Nats have allowed the opponent to score at least one run in the first inning in each of their past 10 contests. They are 2-8 in those games.

"It's tough for the guys,” said manager Dave Martinez. “It really is. You are on the field for a while, and all of a sudden you’ve got to come back. A lot of times, it takes the aggressiveness away from the hitters because they want to give their pitcher some time to settle down a little bit. Good news is we get to hit first [Monday]. And hopefully, we will score first."

The Dodgers racked up four runs on six hits, one walk and a hit-by-pitch off starter Trevor Williams in the first two frames. Jason Heyward got to the right-hander with a two-run single in the first, and James Outman led off the second with his 19th homer. Williams has surrendered 12 homers over his past six starts.

"We are going to give up runs, whether it's the first inning or anywhere in between,” Williams said. “All we can control is what we execute. And for myself, I thought I executed in that first inning. It's just one of those where [Heyward] put a good swing on the ball, and it found a hole. From that point, you are just trying to limit damage and try [to] provide shutdown innings when you can.”

Williams bounced back in the third and fourth frames, striking out two and forcing Freddie Freeman to ground into a double play to prevent the Dodgers from adding to their lead.

The right-hander, who threw 101 pitches (55 strikes) in 4 1/3 innings, struck out four and gave up six runs on eight hits, four walks and the hit-by-pitch. He departed with two on and one out in the fifth as the rain started to come down.

"High leverage, that wears on you,” Martinez said of Williams’ outing. “We tried to stretch him out as long as we could, but we had to get him out of there. We knew the rain was coming. We were hoping he would get out of that inning before we had to put somebody else in the game, but I couldn't do it anymore. He had [101] pitches."

After the 58-minute rain delay and two outs from Mason Thompson, Joe La Sorsa took over and was a bright spot for the Nats. The reliever tossed 3 2/3 innings of scoreless ball.

On a weekend mired in rain delays and extra-inning affairs, the left-hander saved a tired bullpen with a trip to Pittsburgh and Milwaukee looming on the horizon.

"That was awesome,” Martinez said. “He saved our bullpen big time. We penciled him in for about 45 to 50 pitches. He did a great job. He was pumping strikes. That's the key -- he's throwing strikes. What a great job he did."

La Sorsa, who started the season with the Rays, has been up and down this season between Triple-A Rochester and the big league club.

"It's part of the job description,” La Sorsa said. “You’ve got to either put up or shut up with it because if you are going to make it in this game, especially someone in my position, you’ve really got to take a stoic approach. Just internalize everything. I don't want to complain about it because they are giving me an opportunity up here.

“Yes, you obviously have to make the most of it, but I definitely don't want to be that rookie whining and complaining about it. You really just have to put your head down and earn it. Everything in this game you’ve got to earn."

So does the southpaw wake up and not know if he’s in upstate New York or downtown D.C.?

"I wake up in the middle of the night thinking I am in a different place, to be completely honest with you,” La Sorsa said. “But it's all part of the process. I am being given a really good opportunity. I just want to keep on rolling with it. Wherever I am at, if I'm in [the] Minors, Majors, I’ve just got to come in and throw strikes. That's all you can do."