SEATTLE — Canada, your champion awaits you.

If James Paxton wasn’t mentioned in a conversation among the best left-handers in baseball, he made a maple-sized case to be last week against the Oakland Athletics.

And that conversation should probably include the word “Eh” 16 times — as in a career-high 16 strikeouts for Paxton.

It’s a start that will be the benchmark for the rest of Paxton’s season, starting with his next start for the Seattle Mariners in Paxton’s Canadian homeland on Tuesday against the Toronto Blue Jays.

The native of Ladner, British Columbia, is the first Canadian-born player in major-league history to strike out 16 batters in a game. Former Mariner Erik Bedard held the previous mark when he struck out 15 as a member of the Baltimore Orioles in 2007.

“That was pretty cool,” Paxton said. “It was a lot of fun to be out there pitching and racking up those strikeouts.

“It was a big step forward for me.”

Shame that it came in a Mariners loss.

How many times has a pitcher not allowed a run, struck out at least 16 batters and his team eventually lost the game? Paxton was the third since 1908, joining the Padres’ Jake Peavy (2007) and the Indians’ Sam McDowell (1965).

And a Mariners pitcher hadn’t struck out that many in a game since Randy Johnson towered on their mound more than 20 years ago. It was the most single-game strikeouts by a pitcher in the major leagues this year until the Astros’ Gerrit Cole matched that two days later with 16 strikeouts in nine innings in an 8-0 win over the Arizona Diamondbacks.

“I probably had the best fastball I’ve had of my career,” Paxton said. “It was jumping. We were using the top of the zone and guys were swinging right through it.”

Paxton tipped his cap as he walked to the dugout amid a Safeco Field’s roaring crowd — and certainly no section was louder than Paxton’s Maple Grove fan section in the upper deck in left field — after he had Jake Smolinski chasing a 97-mph fastball to end the seventh inning. That was his final pitch in milestone start, leaving with a 2-0 lead.

But Paxton has hurled screaming fastballs to the plate before. What made this different?

Mariners pitching coach Mel Stottlemyre Jr. said the life and spin on Paxton’s four-seamer was the best he’d seen, burying hitters with it up in the strike zone.

“It was an electric fastball,” Stottlemyre said. “There’s times he feathers and tries to make a perfect pitch early and it really sucks that life out of his fastball. We’ve talked a lot about what he’s capable of being and having that plus-fastball and not taking that stuff down and letting guys off the hook.

“His first fastball of the game was 92 (mph). He feathered it in. And the second one was 94 and the third one was 96 and from that point on he got going.”

Stottlemyre watched plenty of Johnson when he was with the Diamondbacks organization. This left-hander was quite similar.

“Man, no doubt,” Stottlemyre said.

“And I tell you, the one thing he did so well — and he’s come along ways — is being able to read barrels. He knew he had a good fastball and he was just changing the eyes all night. That was a difference-maker.”

Paxton threw 105 pitches, 80 for strikes. He pounded the zone and overpowered hitters, once hitting 98.7 mph.

He threw 76 fastballs, 12 cutters and 11 knuckle curveballs. That’s a lot of relying on one pitch.

But he struck out every batter he faced in the A’s lineup at least one time, except for hot-hitting second baseman Jed Lowrie. He fanned Chad Pinder, Khris Davis and Stephen Piscotty three times each.

“Paxton was gross today,” Athletics utilityman Mark Canha said after the game.

“Paxton had great stuff tonight and was handing it to us,” said A’s coach Bob Melvin. “I lost count of the strikeouts on my card.”

At some point the Mariners will stretch Paxton to 115-120 pitches. Not last Wednesday.

The Mariners reasoning for pulling Paxton after seven innings — he threw 25 pitches that final inning. Paxton acknowledged that if he wouldn’t have thrown ball four with two strikes against Jonathan Lucroy the second-to-last batter he faced, he probably would have been pitching in the eighth.

“He had spun some bullets that inning,” Stottlemyre said. “You have to have your horse out there and I know you need to let him run, but you can’t let it get ahead of the barn in every game and all year long if we’re trying to keep him healthy.”

And they are. Health has been one of the few things holding Paxton back the past couple of years, and why he went to lengths this offseason to make sure he’s as healthy as possible, including blood testing and muscle activation techniques.

“This ball club, this rotation needs our big three guys to stay healthy,” Stottlemyre said.

Paxton, aka “The Big Maple,” was three strikeouts shy of the Mariners’ all-time record. Randy Johnson struck out 19 batters in two different games in 1997.

But only Paxton, Johnson, Mark Langston and Mike Moore have struck out at least 16 batters in a game for the Mariners.

“Really from the get-go that was as lively of a fastball as I think I’ve ever seen Paxton have,” Mariners manager Scott Servais said. “Definitely a great outing by him.

“He had all of the pitches working but the fastball was just so dominant tonight. He got it down in the zone early and elevated it late and the punch-outs just started racking up and it was fun to watch. It really was.”

Paxton’s previous career-high was 10 strikeouts, which he’d accomplished twice already this season.

“They know he’s coming after them with the fastball,” Servais said. “But Paxton has some deception, he’s got a steep angle.

“To be that dominant at this level is pretty amazing — and pretty much with one pitch. I know he’s disappointed we didn’t get the ‘W’, but that’s about all you can ask of any pitcher. That certainly was busting right through. He has that kind of stuff, he just hasn’t consistently gone out and done that. That’s what we need from him to ultimately get where we want to go and that’s get to the playoffs.”