SEATTLE -- David Dellucci has been working hard on hitting left-handed pitching. It paid off Sunday.
"To have success against a left-handed pitcher, it takes repetition," said Dellucci, who hit only .107 (3-for-28) against lefties in 2004. "I knew I'd be a little more comfortable the second time around."
Thornton (0-2) walked Dellucci in the fifth inning.
Mark Teixeira led off the seventh with a double off Thornton. One out later, Dellucci reached the second deck in right field with his first homer of the season.
"It feels good to get the win, but I think what's on everybody's mind is that we haven't even started playing our best baseball," Dellucci said. "We came from behind a lot last year, so we feel very comfortable when we're down a few runs. Being behind doesn't phase us."
The Rangers seem to have figured out how to win at Safeco Field. After going 0-11-2 in their first 13 series at Seattle's ballpark since it opened in 1999, Texas has won two straight.
Texas now heads home to Arlington for their season opener.
"It will be nice to finally have some fans in our corner," Rangers manager Buck Showalter said. "We're looking forward to the emotion of opening day with our fans."
The Rangers scored five runs in the fourth with some help from a Seattle fan. After Dellucci walked with one out, Mariners starter Gil Meche gave up three straight hits, including Adrian Gonzalez's RBI single.
Next up, Rod Barajas hit a foul ball down the right-field line that Ichiro Suzuki moved into position to catch. But a fan reached up and caught the ball. The spectator offered the ball to Suzuki, who stared at the fan before walking away.
Mariners manager Mike Hargrove didn't complain about the fan's nice catch.
"It happens at every ballpark," Hargrove said. "The umpire had a good view on the ball. Had Suzuki been denied a chance to catch the ball, he would have called the hitter out."
Barajas took advantage of his second chance to hit an RBI double and give Texas a 2-0 lead. The Rangers added another run when Willie Bloomquist misplayed Alfonso Soriano's grounder for an error. Michael Young made it 5-0 with a two-run single, chasing Meche.
"I just couldn't get that inning over with," said Meche, who in his two starts has allowed nine runs -- seven earned -- over eight innings. "This wears on you."
Young had three hits, and has at least one in all six games this season.
Richie Sexson helped give the Mariners a 6-5 lead with an RBI doubled in a three-run fourth and a two-run double in a three-run fifth.
Matt Riley (1-0) started the sixth in relief of Ryan Drese and allowed a hit to Suzuki. It was the only hit allowed by Rangers relievers Riley, Doug Brocail, Ron Mahay and Francisco Cordero over the final four innings.
Cordero pitched a perfect ninth for his second save.
"We know that if we keep it close, there's a good chance that someone is going to hit one out," Brocail said of the Rangers' potent offense. "When I sit and watch from the bullpen, I feel a little sorry for the opposing pitchers because when we break out, forget about it."
Thornton pitched 3 1/3 innings in relief of Meche, allowing three hits and the two runs.
Each of the Rangers' seven homers this season have come in the seventh inning or later. ... Mariners fans at the game received Dan Wilson T-shirts, and he responded with his first two hits of the season... The Mariners have committed five errors, leading to eight unearned runs.