Seattle, afterall, entered the game with the best road record in baseball at 30-15. And despite struggling as of late, they did still hold the best overall record in the American League at 55-31.
The Rangers, meanwhile, were just 34-52, good for the third-worst record in the AL.
On top of that, Seattle sent Gil Meche to the mound, their 24-year-old 10-game winner.
All that didn't matter once the game started, however, as the Rangers got to Meche early and cruised to victory behind the stellar outing of Ismael Valdes, winning 5-1.
Valdez, a late-season acquisition by the Mariners in 2002 before returing to Texas as a free agent prior to the season, allowed just one run on four hits through six innings to pick up the win. He improved to 7-5 on the year.
Rosman Garcia and Francisco Cordero held Seattle scoreless the rest of the way.
The Mariners had just five hits on the day.
Edgar Martinez's solo homerun in the fourth, his 18th of the season, represented Seattle's only run.
The Mariners (55-32) lost a game on their AL West lead over Oakland. The Athletics beat Anaheim Sunday to pull to within six games with a week to go before the all-star break.
Meche, who was snubbed for the all-star game, had one of his worst outings of the season. He went just four innings, walked three, and gave up five runs.
Texas (35-52) did most of its damage in the second inning. A leadoff single by Juan Gonzalez and consecutive walkes to Kevin Mench and Ryan Ludwick loaded the bases with nobody out. Two batters later, Doug Glanville singled, scoring two, then Michael Young grounded out and Ludwick scored on a throwing error by Mark McLemore at second base.
The Rangers made it a 4-0 ballgame when Rafael Palmeiro belted a solo homer in the third, his 20th of the year.
Edgar's blast put the M's on the board in the fourth and made it 4-1, but that's as close as the vistors from the Northwest would come.
Young homered in the fourth to cap the scoring at 5-1.
Meche (10-4) took the loss.