ST. LOUIS -- Off the bat, it appeared destined to be a double, sailing and slicing into the unseasonably crisp St. Louis night before Julio Rodríguez glided into the gap.

Seattle’s center fielder made the route look routine as he ran the liner from Alec Burleson down and in deceleration crossed his wrists signaling his trademark “No Fly Zone,” but this time in unfamiliar territory on Friday night at Busch Stadium.

It was only one out among the Mariners’ 27, but it was the headliner within a game full of defensive gems from Seattle’s gloves, the totality of which allowed Bryce Miller to easily coast through six scoreless innings en route to a 6-1 victory over the Cardinals.

With the win, the Mariners remained 4 1/2 games from first place in the American League West behind the Astros, who ran away to victory vs. Arizona, and 4 1/2 games back of the final AL Wild Card spot.

Josh Rojas vacuumed three hard-hit balls at the hot corner, J.P. Crawford snowconed a 98.7 mph liner from Paul Goldschmidt, while the Mariners overall played clean for nine full innings to allow Miller to coast.

“I didn't think anybody was getting to that one in the sixth and Julio came out of nowhere from a mile away and got to it,” Miller said. “So that was cool. And then next pitch, J.P. shows off his bunnies, so, yeah, I'll take it.”

Miller had run support via a bases-loaded sacrifice fly from Randy Arozarena in the fifth and a two-run homer from Dylan Moore in the sixth. But the Mariners’ most monumental moments -- and above all, those telling of what they’ve long hoped that their offense can become -- came from three huge insurance runs in the ninth.

Four knocks in the first five at-bats -- from Mitch Haniger (0-1 count), Rodríguez (1-2), Cal Raleigh (3-0) and Luke Raley (first pitch) -- led to that dagger of an inning, further underscoring Raleigh’s recently preaching urgency of “playing the full nine.”

Over the Mariners’ three-game win streak, they’re 38-for-115 (.330) with a .968 OPS. They finished with 11 hits on Friday, marking the first time all season that they’ve had more than 10 in three straight games.

Perhaps as telling, the Mariners only struck out five times on Friday, a low they’ve reached only eight times this season and once in the second half.

“As a group, we simplified a bunch of stuff,” Crawford said. “Everyone's going into each at-bat just relaxed and calm and ready to do damage. We all have a plan, and these last couple games, the plan's been simple, and I think everyone's bought into that."

New hitting coach and Hall of Famer Edgar Martinez has been at the forefront of that messaging, which aligns with what he said when he assumed the position two weeks ago.

“Man, he's been huge,” Crawford said. “He's been really good. ... Just the advice he gives is so simple, and it really works way better than anything else.”

The late insurance runs also allowed manager Dan Wilson to avoid using Andrés Muñoz for the second straight game. That was particularly critical given that Seattle’s All-Star closer has recently experienced minor elbow soreness.

As for Miller, he furthered his late-season ascent and is proving to everyone just how capable he is of handling the rigors of a full-season workload.

Miller scattered just three singles and two walks over six scoreless innings, marking the eighth time he’s been scoreless with that length -- an MLB best. He didn’t quite have the elite swing-and-miss stuff he’s shown in recent weeks, with just seven whiffs and four strikeouts, but when he did go for the jugular, he did so dramatically.

Among those K’s included a pair of 96 mph four-seam fastballs that he blew by former MVP Paul Goldschmidt. Miller also unleashed a running two-seamer that induced a goofy-looking golf swing from Nolan Arenado, himself widely considered to be on a Hall of Fame track.

“That’s the ideal one with two strikes,” Miller said of the two-seamer, which he’s leaned on more following consultations with Bryan Woo. “It's over the plate the whole time until, last minute, it ends up two balls in.”

Even including an abbreviated hiccup on Sunday in Anaheim, Miller has been on an upward trajectory for two full months, with a 2.01 ERA, 0.84 WHIP, .545 OPS against, a 24.2% K rate and a 4% walk rate over his past 10 starts.

“Bryce is a dog,” Crawford said.