SEATTLE (AP) -- Washington manager Manny Acta didn't know what to expect against Seattle's R.A. Dickey.
Acta quickly found out the Nationals would not have a problem hitting against the knuckleballer.
"It's the first knuckleballer we've faced," Acta said. "I really didn't know how the guys would handle it, especially since we have so many young guys on our ballclub. But they made Dickey get the ball up and were able to get some good swings on it."
Flores hit a two-run double and Belliard had a two-run single as the Nationals roughed up Dickey for six runs, five hits and two walks in the second.
Dickey (1-2) gave up eight hits and seven runs in 1 2/3 innings. He threw 52 pitches in his second start of the season and first since a 5-4 loss April 18 at the Los Angeles Angels.
"The movement was very minimal, it stayed up a lot," Dickey said. "Usually, the bottom will drop out late. Tonight, it wasn't dropping. It was just hanging for them to hit."
Dickey replaced the struggling Miguel Batista in the rotation. Dickey had allowed one run in 18 innings in his last five relief appearances.
Washington starter Shawn Hill (1-3) allowed 12 hits in five innings, but left with a 7-5 lead.
"I battled through what obviously wasn't a good night for me," Hill said. "But at the same time, anytime you give up 12 hits you're not doing something right. I'll take it with a grain of salt."
Jon Rauch pitched the ninth for his 14th save in 17 opportunities.
The Mariners, who had lost six of seven, scored twice in the third inning on five consecutive singles. They had a chance for more with the bases loaded and no outs, but Richie Sexson struck out looking and Kenji Johjima grounded into a double play.
"Everybody knows he is a battler," Acta said of Hill. "He did it basically with his fastball. He had no off-speed stuff today. He worked himself out of that inning and we were able to hold a victory for him."
Suzuki, who was 3-for-5, stole second with one out. But Hanrahan retired Lopez on a fly to left and Jose Vidro on a deep fly to right.
Seattle's bullpen kept the game close. Ryan Rowland-Smith relieved Dickey and didn't give up a hit in 3 1-3 innings. Shawn Green gave up two hits and struck out four in two innings. Mark Lowe retired six straight batters, including three strikeouts, in eighth and ninth.
The Mariners rallied to cut the lead to 7-5 in the fifth on a two-run double by Johjima off the glove of right fielder Elijah Dukes.
Every Mariner starter had at least one hit.
"We are swinging the bats a lot better," Seattle manager John McLaren said. "We had 15 hits and we didn't have any errors. There are a lot of positive things happening, but we just couldn't get over the hump and get a win."
After the game, Washington placed LHP Odalis Perez on the 15-day DL with left shoulder tendinitis. The Nationals recalled RHP Tyler Clippard from Triple-A Columbus and he was to start Saturday's game. ... The Nationals and Mariners last met in 2005 when Washington swept a three-game series at RFK Stadium. ... Seattle 3B Adrian Beltre was 1-for-27 before he singled in the third inning on his bobblehead night. ... The Nationals set a season high for runs in an inning with the six in the second. ... Suzuki stole his 29th base in the eighth to tie Boston's Jacoby Ellsbury for the major league lead.