Phil Bradley's bases-loaded triple highlighted a five-run seventh inning yesterday that gave the unbeaten Seattle Mariners a 5-1 victory over the Minnesota Twins in Seattle.

The Mariners, who extended the best start in their history to 6-0, and the Detroit Tigers (5-0) are the only unbeaten teams in the American League. Boston and Baltimore both lost for the first time yesterday.

Seattle's Mike Moore (2-0) and Frank Viola (1-1) matched shutouts through six innings. Al Cowens started the seventh for Seattle with a double, his third hit, and Jim Presley was walked intentionally. Spike Owen drove in the first run with a pop-fly single just beyond the reach of second baseman Tim Teufel.

Harold Reynolds walked to load the bases and Rick Lysander relieved Viola. Bradley, who beat the Twins with a two-out ninth-inning grand slam Saturday, lined an 0-2 pitch to right-center to clear the bases. Bradley scored on a single by Alvin Davis.

"Being 6-0 doesn't surprise me. We have a good team with a great pitching staff," said Owen.

"I think we're opening some people's eyes," said Bradley. "The key is we have to keep on believing in ourselves. All of the breaks have been going our way. The Detroit Tigers did the same thing last year and I don't think that the breaks ever caught up with them."

The Mariners opened the season with a six-game homestand and play their next nine games on the road.

"I guess I hate to leave the Kingdome," Bradley said. "When we get on the road we'll see where we're at."

The Twins scored in the eighth on Tom Brunansky's two-out double and a single by Mike Stenhouse. Edwin Nunez relieved Moore and got the final four outs.