WASHINGTON -- Before the Nationals rallied for six runs in the bottom of the ninth inning to defeat the Athletics, 8-7, on Sunday afternoon, there was a lot for A’s fans to cheer about.

That was particularly the case for a large group sitting behind the A’s dugout at Nationals Park -- there to support rookie second baseman Zack Gelof. He gave them a lot to cheer about, as he hit two homers and added a pair of singles that helped Oakland build a 7-1 lead.

The contingent of 50 to 100 A’s supporters were Gelof’s family and friends from his hometown of Rehoboth Beach, Del., who made themselves seen in their A’s jerseys and heard throughout the three-game series.

“My friends and family were here most of the weekend, so it was cool,” Gelof said after his first Major League multihomer and four-hit game.

Gelof, ranked as the A’s No. 3 prospect by MLB Pipeline, now has eight home runs in 25 games since being called up from Triple-A Las Vegas on July 14.

The second baseman is the fourth Oakland rookie to record four hits and two homers in the same game since the franchise moved to the Bay Area from Kansas City in 1968.

"Zack’s come to play,” A's manager Mark Kotsay said. “The day he had at the plate is special, and he continues to go out and play hard and be a big contributor to this offense right now.”

Gelof started the A’s off in the first inning against Trevor Williams, homering to center on a 2-1 fastball. The Statcast-projected 433-foot shot gave Oakland a 1-0 lead that quickly became 3-0 when Seth Brown went deep two batters later.

“Just trying to keep it simple,” Gelof said. “Do damage on something I can handle. Just have fun. I tried to do that.”

In the third, Gelof helped manufacture a run when his single advanced JJ Bleday to second. Bleday scored on a single by Aledmys Díaz to make it 4-1.

Gelof led off the fifth inning and crushed a first-pitch fastball from Williams. Alex Call appeared to have a play as he drifted back to the center-field wall, but he looked up and watched the ball land just beyond the fence for Gelof's second homer of the game, increasing the lead to 5-1.

“I knew I hit it good,” Gelof said. “Just pretty high. It ended up barely getting over. Happy with that result, just obviously not the loss.”

Gelof struck out in the seventh inning, but he ended his day at the plate with a single in the ninth. Washington then staged a dramatic rally and walked off Oakland for the second game in a row.

“I think all we can do is show back up tomorrow and keep getting after it, because that’s the only option,” Gelof said.

Gelof finished the series 6-for-12 with two doubles, two homers and three runs scored.

“Stay focused and have fun,” the 23-year-old said of his approach since arriving from Las Vegas. “Stay in the game and watch other guy's at-bats. Just try to win. Anything that I’m doing, both sides of the ball -- defense and offense -- just try to do my best.”

Gelof has reached base safely in each of his 11 games in August, while batting 15-for-41 (.366) during that stretch. He has at least one extra-base hit in 16 of his 25 career games since being called up. He has seven homers in his past 14 games.

“He did a lot of great things in Spring Training to try and make the club. Starting in Triple-A, he had a phenomenal year there,” Kotsay said. "I think the time was right to bring him here and the confidence is there. He’s a baseball player. It’s fun to watch him play, and we’re going to continue to watch him for a long time I think.”