(SportsNetwork.com) - Even when Bryce Harper gets thrown out of a game, it ends up helping Washington to a win.

Harper and the Nationals eye a seventh victory in eight games on Thursday night when they begin a four-game series with the San Diego Padres.

The red-hot Harper went into Wednesday's finale of a three-game set with the Arizona Diamondbacks having hit .565 with seven homers, 16 RBI and 11 runs scored over his previous six games. He then went 1-for-3 with a walk in the finale, but was tossed in the seventh inning for arguing a called third strike on a check swing.

Manager Matt Williams also was ejected for defending Harper, who was replaced in right field by Michael Taylor. All Taylor did was answer the Diamondbacks' go-ahead run in the bottom of the eighth inning with a grand slam in the top of the ninth that led to a 9-6 win.

Jayson Werth and Tyler Moore also homered for the Nats, who got all nine of their runs on homers. Starter Gio Gonzalez allowed five runs on nine hits in five innings.

"They had a lot of opportunities, but we were able to get the last swing," said Williams.

Doug Fister will start this opener for the Nationals and is 2-1 with a 2.87 earned run average through six starts.

Fister hurled 6 1/3 shutout innings to beat the New York Mets on May 3 and turned in another quality outing six days later against Atlanta. However, the righty didn't factor into his club's 8-6 win after yielding three runs on six hits over 6 2/3 innings. He didn't walk a batter and fanned three.

Fister will face the Padres for the second time and took a complete-game loss in the initial meeting, giving up a run and striking out seven.

The Padres hope that Tyson Ross can pick up his first victory since April 12 with tonight's start.

Ross is 1-3 with a 3.98 ERA on the year and had lost three straight starts before getting a no-decision in Arizona on Saturday. He gave up just two runs for a second straight outing and also scattered five hits and a pair of walks over six innings, striking out six.

The right-hander has yielded three or fewer runs in all but one of his seven starts and is 0-1 with a 4.76 ERA in four games (1 start) against the Nats.

San Diego wrapped a quick two-game set with the Seattle Mariners by winning Wednesday's clash 4-2. Will Middlebrooks homered and Cory Spangenberg notched two hits, an RBI and a run scored as the Padres halted a two-game slide.

James Shields earned the win after surrendering just one run on six hits and three walks with nine strikeouts. He became the sixth pitcher in franchise history to start a season 5-0 and the first since Justin Germano in 2007.

"It was a grind today, for sure. I got out of some jams and the team did a good job of scoring some runs," Shields said.

The Nationals have won seven of their past 10 against the Padres.