Although this has been far from his best season, Felix Hernandez enjoyed one of his finest moments as the pitching ace of the Seattle Mariners last weekend.

As he exited the mound after blanking the Toronto Blue Jays for seven innings in a game critical to the playoff hopes of both teams, King Felix screamed, “This is my house!” That was a message to the invading Toronto fans who represented the majority of spectators at Safeco Field — and to the so-called Mariner faithful who allowed it to happen.

In what was one of their most important home series in a decade, the M’s were playing in front of what amounted to a hostile crowd. That was undoubtedly infuriating to the players and an embarrassment to the Mariner fan base.

This was far from a surprising development. Ever since the two franchises were formed (the Mariners and Blue Jays joined the American League in the same year, 1977). Toronto backers have migrated in droves from British Columbia and Alberta to support their national team.

Nor is this situation isolated to the Blue Jays. In home games against the likes of the Boston Red Sox, New York Yankees, San Francisco Giants, Los Angeles Dodgers and other teams with high national profiles, Mariner fans are likely to be in the minority. A friend of mine who lives in Seattle won’t attend Mariner games against Toronto or Boston because he dislikes being surrounded (and often harassed) by supporters of the visiting team.

Taking note of the spectator ratio after the first game of the Toronto-Seattle series, a Seattle columnist blamed it all on the M’s. The Mariners, he contended, brought the situation on themselves through their 15-year playoff drought and a disturbing habit, even this year, of performing badly in front of large home crowds.

The column was well-reasoned and written. I have a one-word response to its conclusion.

Hogwash.

The University of Washington hasn’t beaten Oregon in football since 2003 (incredibly, the Ducks have covered the point spread every year since), but I haven’t noticed Oregon fans taking over Husky Stadium in the years the game has been played in Seattle.

Even in a down year, it’s almost unimaginable that the Seahawks’ “12th men” would allow themselves to be outnumbered by Denver or San Francisco supporters.

More to the point, a Canadian baseball takeover seemingly hasn’t occurred in places like Detroit, which is even closer to the border than Seattle. As is the case in Boston, St. Louis and Chicago (at least with the Cubs), Detroit has the reputation of being a good baseball town – a community that will support its home franchise regardless of its record.

Whatever the Latin is for fair-weather baseball fans, Seattle belongs in that species. Mariner home attendance regularly topped the 3 million mark during the team’s glory era from 1997 through 2002, but fell off in direct proportion to the team’s performance decline.

Although the M’s have contended for playoff berths in two of the past three seasons, there has been no significant revival at the box office. Entering Wednesday’s game with the 13th best record in the majors, the Mariners rank 19th in home attendance — and that figure is padded by supporters of the visiting club.

When a franchise endures a long postseason drought, it’s only natural that its fan base turns to more successful options. In most cases, however, that group is outnumbered by those who jump on the bandwagon when the home club improves. For some reason, that hasn’t happened in Seattle.

The second worst part of the Canadian takeover of Safeco Field is that there isn’t anything the Mariner management can do to stop it. Clearly, Blue Jay supporters are purchasing tickets en masse as soon as they go on sale the previous winter.

Seated in the Safeco Field press box prior to a Seattle-Toronto game a couple of years ago, I was mildly surprised to see spectators wearing Blue Jay uniform tops streaming into the choice seats directly behind home plate as soon as the gates opened. That indicates that Mariner season ticketholders are contributing to the malady by selling their seats to Toronto boosters.

The saddest part of the situation is that Mariner on-field performance could be — and probably has been — affected. Seattle already has several strikes against it (lack of traditional success, long road trips, few endorsement opportunities) in attracting and retaining elite players. Playing home games in front of hostile audiences doesn’t help.

The Mariners will stage Fan Appreciation Night on Friday. In the future, they might consider relocating it to Vancouver or Calgary.