SEATTLE -- Felix Hernandez saw a right-handed batter on deck and decided he didn't want anything to do with Jay Gibbons.
Hernandez's intention to pitch around Gibbons instead ignited Baltimore's offense.
Gibbons' three-run homer in the sixth inning gave Baltimore the lead for good, and made a winner out of Jeremy Guthrie in the Orioles' 8-3 win over the Seattle Mariners on Tuesday night.
Gibbons, struggling most of the season and hitting just .212 entering Tuesday, added a two-run single in the eighth and finished with a season-high five RBI.
"I know I haven't done anything. I'm a guy who expects to drive in runs and I haven't driven in anybody this year," Gibbons said.
Nick Markakis matched his career-high with four hits and the Orioles offense broke out with 14 against the best team in the American League during the last six weeks.
Hernandez, Seattle's 21-year-old ace, was already in a jam in the sixth inning when Gibbons stepped in. Markakis started the inning with a double -- one of his four hits -- and then walked Aubrey Huff to put two runners on with two outs.
With right-handed hitting Chris Gomez on deck, Hernandez (6-5) fell behind 2-0 to Gibbons. His next offering was an 89 mph slider that hung over the middle of the plate. Gibbons jumped on the pitch, hitting it just inside the right-field foul pole, clanging his sixth homer of the season off the facing of the second deck in right.
"I was frustrated," Hernandez said. "Those guys gave me the lead and I couldn't hold it."
Hernandez was pulled after the sixth. He gave up eight hits and three walks while striking out five. It was his first loss since June 15 against Houston.
The three runs were all Guthrie (5-3) needed. He won for the first time since June 20 against San Diego, a span of four starts. He shook off three errors by his defense that forced him to throw some extra pitches, and held Seattle to just six hits and two runs in six innings.
"He kept his poise and I think that's what makes Guthrie so special. He has poise," Baltimore interim manager Dave Trembley said. "He doesn't give in. He doesn't alter his approach."
Baltimore's offense didn't rest after Gibbons gave the Orioles the lead. Baltimore added five runs against Seattle's bullpen in the seventh, sending 10 batters to the plate. Luis Hernandez started the rally with a four-pitch walk against Eric O'Flaherty, and scored on Brian Roberts' double to deep left-center.
O'Flaherty was charged with all five runs. Gibbons capped the inning with a two-out, two-run single off Ryan Rowland-Smith that fell just in front of a sliding Ichiro Suzuki.
"I've felt fairly comfortable this month," Gibbons said. "I'm just trying to do as much as I can when I'm in the lineup."
Seattle took advantage of the first of Baltimore's three errors in the third. Suzuki reached on a fielder's choice, and with one out stole second. He went to third as the throw from Ramon Hernandez sailed into center field and scored on Jose Vidro's RBI single. Vidro advanced to second on the play as Corey Patterson booted the ball in center, but was stranded.
Kenji Johjima lined a solo homer in the fourth, but Guthrie held Seattle to two hits after that point. Key for Guthrie was fielding Raul Ibanez's comebacker and starting a double play after Vidro led off the fifth with a single.
"He had to make some extra pitches early in the game because he had a couple of misplays behind him, but when he fielded that comebacker and turned that double play I thought the momentum came back on our side," Trembley said.
Guthrie was coming off his worst outing of the season, lasting just 3 2/3 innings and giving up five earned runs and nine hits against the White Sox last Thursday.
Gibbons has three homers in the last two weeks. Before July 4, Gibbons hadn't homered since May 14. ... Baltimore's five-run seventh inning was the Orioles' 15th inning this season of four runs or more. Last year, the Orioles led the majors with 56 innings of four runs or more. ... Tuesday was the 28th anniversary of the 50th All-Star Game, played at the Kingdome in Seattle.