CINCINNATI — Jonny Gomes had hit three home runs in a game once before. This time meant more to him.

Gomes homered in his first three at-bats to back Bronson Arroyo’s two-hitter and the Cincinnati Reds beat the Washington Nationals 7-0 on Thursday night.

The three-homer game was Gomes’ first since July 30, 2005, against Kansas City.

‘‘This one’s a lot more emotional for me,’’ said Gomes, who opened the season with Triple-A Louisville after signing a minor-league contract with Cincinnati in January. He joined the Reds on May 22. ‘‘I was in Triple-A to start this thing off, and now — not too many at-bats later — I have three home runs.’’

Gomes hit two-run homers in the second and fourth innings and added a solo shot in the sixth to help the Reds take a 7-0 lead. He struck out in the eighth inning, but still finished with a single-game career-high five RBI.

He is the sixth player to hit three homers in a game this season. Pittsburgh’s Andrew McCutchen was the last on Aug. 1.

Gomes became the 24th player in franchise history to hit three home runs in a game and Ryan Hanigan added a solo shot to give Arroyo plenty of breathing room.

Gomes’ performance reminded manager Dusty Baker of games he’s seen from all-time home run leader Barry Bonds and Dave Kingman.

‘‘That was one the best performances I’ve seen in a long time,’’ Baker said. ‘‘We needed those runs and the victory, and that was an outstanding performance by Bronson, too. It was like he didn’t break a sweat.’’

Arroyo (11-11) had been 0-3 in his previous four starts and hadn’t won since beating Milwaukee 4-0 on July 17. He allowed just one runner as far as second base.

Reds’ boxscore

Thursday’s Game

Reds 7, Nationals 0

Washington Cincinnati

ab r h bi ab r h bi

Morgan cf 2 0 0 0 Dickrsn cf 4 0 0 0

Brgmn p 0 0 0 0 AlGnzlz ss 4 0 0 0

SRiver p 0 0 0 0 Votto 1b 2 1 0 0

MacDgl p 0 0 0 0 BPhllps 2b 4 0 1 1

WHarrs ph 1 0 0 0 L.Nix lf 4 2 2 0

CGzmn ss 4 0 0 0 Gomes rf 4 3 3 5

Zmrmn 3b 4 0 1 0 ARosls 3b 3 0 0 0

Dunn 1b 2 0 1 0 Hanign c 4 1 2 1

Wlngh lf 3 0 0 0 Arroyo p 3 0 0 0

Dukes rf 3 0 0 0

J.Bard c 3 0 0 0

AlGnzlz 2b 3 0 0 0

Balestr p 1 0 0 0

JPadill ph-cf 2 0 0 0

Totals 28 0 2 0 Totals 32 7 8 7

Washington 000 000 000 — 0

Cincinnati 030 201 10x — 7

DP—Cincinnati 1. LOB—Washington 3, Cincinnati 4. 2B—B.Phillips (20), L.Nix (22). HR—Gomes 3 (14), Hanigan (2).

IP H R ER BB SO

Washington

Balester L,1-2 5 5 5 5 2 2

Bergmann 1 2 1 1 0 1

S.Rivera 1 1 1 1 1 0

MacDougal 1 0 0 0 0 1

Cincinnati

Arroyo W,11-11 9 2 0 0 1 3

HBP—by Arroyo (Morgan). Umpires—Home, Tim McClelland; First, Andy Fletcher; Second, Greg Gibson; Third, Angel Campos. T—2:07. A—16,889 (42,319).