Mariner batters unloaded for 15 hits off starter Jon Lester and two relievers, Justin Smoak and Michael Saunders each delivering with a pair of doubles apiece, Smoak adding a dingle to finish 3-for-4 with two RBI and two runs. Saunders was 2-for-4 with three ribbies and two runs.
The win was the second straight for the Mariners, who are still not a factor in the AL West, 12 1/2 games off the pace being set by Oakland.
Game two of the series begins Tuesday night at 7:10 pm PDT in Seattle.
NOTABLE: In Oakland's 2-1 win over Pittsburgh, A's closer, Grant Balfour, converted his 23rd consecutive save opportunity of the season, and 41st overall, dating back to last year, breaking the A's record of 41 straight set by Dennis Eckersley in 1991-92. It's the third-longest consecutive save streak in MLB history.
Lannan, who missed two months with injuries between the middle of April and the middle of June, improved to 2-3 on the year with eight shutout innings on four hits and two walks, fanning four.
After 109 pitches, manager Charlie Manual's decision to sit Lannan down for the ninth inning in favor of closer Jonathan Papelbon nearly backfired as Papelbon allowed Washington to score its only two runs of the game in their final at-bat. The shaky closer finally got the job done, dubiously earning his 19th save, while making Lannan, who clearly threw his best game out of eight starts this season, sweat out the victory.
The win moved Philadelphia closer to Washington in the NL East standings, where they both trail the Braves - Washington by five games and Philly by 7 1/2.
The contest was the first of four between the two East division contenders; game two scheduled for Tuesday at 7:05 pm EDT.
Today's Trivia: The longest consecutive streak of saves in the major leagues is 54. Which pitcher holds that remarkable distinction?
Yesterday's Answer: Atlanta's Tom Glavine tied for the NL lead in wins in 1991, 1992 and 1993, then led outright in 1998 and 2000, winning 20 games three times, 21 in 2000 and 22 in 1993.