WASHINGTON – Ervin Santana's pitching line wasn't bad Sunday, but it was how he arrived at his three runs allowed in six innings that was problematic for a Braves offense that can look awful some days, like it did on this one.

The Nationals scored two runs in the first inning and cruised to a 4-1 win against the Braves to finish with a split of a four-game series and move back to 1 ½ games ahead of second-place Atlanta in the National League East standings.

Evan Gattis’ 20-game hitting streak ended and Braves Chris Johnson and Justin Upton were ejected for arguing after strikeouts, Johnson in the sixth inning and Upton in the ninth.

Before losing the last two games of the series, the Braves had won 24 of their previous 31 games against the Nationals including 12 of 15 at Nationals Park. After holding the Braves to just one run and nine hits in two games this weekend, the Nationals improved to 3-7 in the season series between the teams.

The closest thing to fireworks produced by a Brave with a bat in his hand Sunday came when Johnson was ejected from the game in the sixth inning after pointing and cursing at first-base umpire Tim Welke, who had rung him up on an appealed check-swing call for the second out with runners on first and second.

Justin Upton had just singled to drive in the Braves’ only run and cut the lead to 3-1 when Johnson came up with a chance to tie or put the Braves ahead with a base hit. Replays appeared to show that he indeed checked his swing, but Welke called him out and Johnson was furious.

Home-plate ump Mark Carlson tossed him after Johnson began pointing and shouting at Welke. Johnson, who has become known for his volatile temper, continued to point and shout at Welke all the way to the dugout and from the dugout before heading to the clubhouse.

Braves manager Fredi Gonzalez came out and argued with Carlson briefly before returning to the dugout. Johnson and Upton’s ejections were the fourth and fifth of the season for the Braves.

The Braves have lost 12 of 19 games and scored three runs or fewer 10 times in that stretch. After going 0-for-5 with runners in scoring position in Saturday’s 3-0 loss, they went 1-for-7 in those situations Sunday. They had two on when Justin Upton grounded out to end the fourth inning, and two on when B.J. Upton struck out to end the fifth inning.

Tanner Roark (6-5) allowed four hits and one run in 5 1/3 innings, with three walks and three strikeouts.

Santana (5-5) gave up six hits, three runs and one walk with nine strikeouts in six innings. He fell to 1-5 with a 5.96 ERA in his past eight starts after going 4-0 with a 1.99 ERA in his first six.

He has four “quality starts” in his past five games, albeit with just the minimum requirement for that classification – three earned runs in six innings — in three of those starts.

The Nationals had a 2-0 lead after sending their first five batters to the plate in the first inning. Anthony Rendon walked with one out, Jayson Werth and Adam LaRoche each singled (the latter driving in a run), and Ryan Zimmerman added a sacrifice fly before Santana struck out Ian Desmond.

Santana struck out two consecutive batters in each of the next three scoreless innings, including Werth and Laroche with a runner at third in the third inning.

The Nationals pushed their lead to 3-0 in the fifth inning on a leadoff single by Sandy Leon and Denard Span’s one-out double. They scored again in the eighth on a wild pitch by Luis Avilan, a run charged to rookie reliever Shae Simmons.

For a write-thru version of this game story with postgame quotes and other updates, go to MyAJC.com Braves page or click this link.