SAN DIEGO -- Even before the Padres' current run of terrible interleague play began, there was no pretense that they were built to hang with the powerful teams of the American League.

Since their inception in 1969, the Padres have always been a pitching-and-defense kind of franchise. It's a style in direct conflict with the spirit of interleague play, as AL teams stockpile hitters and easily fill out nine-deep lineups while the Padres struggle to find a suitable designated hitter.

The Padres' interleague losing streak reached a major league record 13 games after a 4-3 loss to Seattle on Wednesday night at Petco Park, further illustrated their inability to hang with teams in the Junior Circuit. The Padres lost for the 20th time in their last 23 interleague games and fell to 83-116 against the AL. Their .417 winning percentage ranks 29th out of 30 major league clubs, with only the Pittsburgh Pirates worse at .385.

"We've always been a pitching club as opposed to a big offense, and most American League clubs are built on offense," general manager Kevin Towers said of the Padres, who have been outstcored 81-30 during a losing streak that dates back to a 6-2 home win over the Detroit Tigers on June 20, 2008. "We have a hard time outslugging an American League club."

Since that last interleague victory -- one in which Greg Maddux silenced the Tigers with seven innings of one-run ball -- the Padres have compiled a 5.76 ERA and been out-homered 23-8 by their opponents.

"We've been outpitched and outhit," manager Bud Black said. "I don't think there's any secret to why this is happening."

On Wednesday, the Padres played a game more suited to their style, as pitcher Chad Gaudin struck out eight Mariners in six innings. The Padres also blasted two homers to Seattle's one. But two critical facets of their winning formula -- timely hitting and defense -- were missing.

Shortly after the Padres tied the game at 3 in the fourth inning on Chase Headley's two-run homer into the third deck of the Western Metal Supply Co. building, they gave the lead back on catcher Nick Hundley's throwing error. Making a snap throw to third base, Hundley bounced the ball past Kevin Kouzmanoff, allowing Seattle's Franklin Gutierrez to trot home for a 4-3 lead.

That was just enough, as Garrett Olsen (2-1) and three Mariners relievers limited the Padres to four hits and three walks.

After Seattle pitchers retired 11 of 12 batters, the Padres mounted an eighth-inning rally when pinch-hitter Brian Giles reached with one out on a catcher's interference call. Tony Gwynn Jr. lined out to shortstop before David Eckstein singled and Adrian Gonzalez drew a walk to load the bases.

That left it up to Kouzmanoff, who had ended the team's scoreless streak at 22 innings with a solo home run in the second inning. But Kouzmanoff hit a hard ground ball that Adrian Beltre fielded before tagging third base to end the inning.

"Offensively we couldn't muster anything," Black said. "Four hits, you're not going to do much damage. We've got to get more guys on base to pressure the defense. We've just got to generate more."

Commanding his fastball, Gaudin (2-6) recorded twice as many outs as he did in his last start Friday, when he surrendered eight runs on 10 hits in three innings against the Los Angeles Angels. Attacking hitters from the outset, Gaudin threw strikes on 70 of 103 pitches and limited the Mariners to six hits while walking only two.

Ken Griffey Jr. tied the game with a one-out, one-run double off Gaudin in the fourth inning. Gaudin then made a location mistake on a fastball to Jose Lopez, who sent it into the second deck in left field for a 3-1 lead.

"I thought I had good command of my fastball," Gaudin said. "It's just about getting the rhythm and tempo and knowing you can throw it. I've always been able to do that. It just seems like lately one mistake, or one hitter fouling off pitches, is keeping me from getting guys out earlier. … Every little thing that can possibly happen is happening."