SEATTLE -- The credibility behind Chris Flexen¡¯s breakout over the past six weeks continues to grow with each start, and he advanced his positive trend with another dominant outing Sunday, a 4-1 Seattle win over the Rangers at T-Mobile Park.

The Mariners are 11-4 when Flexen starts and 34-36 with everyone else. They are five games above .500 (45-40) and 3 1/2 games out of the second American League Wild Card spot in huge part due to their big find out of Korea last offseason, a player they scouted exclusively on video.

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Flexen limited the Rangers to four baserunners and one run over 81 pitches in six dominant innings, which secured the Mariners¡¯ third straight series win to match a season high. He likely would¡¯ve gone deeper had he not been on a shorter leash due to the four days of rest he was on compared to the standard five in the construction of Seattle's six-man rotation.

That efficiency helped position Drew Steckenrider, Paul Sewald and Kendall Graveman to pitch the seventh, eighth and ninth innings, respectively, over which they allowed a combined one hit to the 10 batters they faced.

Flexen put Mariners manager Scott Servais in as ideal a spot as possible, which was helped all the more by booming home runs from Shed Long Jr. and Luis Torrens that gave the pitching staff the cushion it needed.

¡°You know he¡¯s going to give you a chance to win the game,¡± Servais said of Flexen. ¡°He is going to keep you in the ballgame. And I'm really impressed with how he continues to develop. ¡­ He attacks. He's really bought into what we believe in here, as far as dominating the zone, going and winning 0-1, 0-0 counts. It's really helped him out.¡±

Since a career-worst start on May 21 in San Diego, Flexen has a 2.62 ERA and has pitched at least six innings in six of his seven outings. The offensive onslaught from the Padres that night was obviously a turning point from a confidence perspective, but Flexen has also fortified the rest of his repertoire in this stretch while fully embracing the Mariners¡¯ mantra of ¡°dominating the strike zone.¡±

Flexen threw first-pitch strikes to 16 of his 22 batters for a rate of 72.7 percent on Sunday, raising his season average to 65.2 percent, which ranks among the top 25 of pitchers who¡¯ve faced at least 300 batters this season.

¡°I think that's the biggest thing that's different, definitely the confidence and trust in myself,¡± Flexen said. ¡°I think the stuff is still very similar, just more fine-tuned and sharpened now.¡±

He¡¯s also shown far more polish and conviction on the changeup that wasn¡¯t talked about nearly as much as his curveball and cutter in Spring Training, after he signed a two-year, $4.75 million deal.

Flexen flashed the changeup 11 times against the Rangers, who went just 1-for-5 against the offering. The biggest sequence for that pitch -- and, really, his entire outing -- was the 3-2 count in which he threw it to Joey Gallo up-and-away with two runners on in the sixth inning.

A mistake or mislocation in that moment against one of the game¡¯s elite sluggers, especially with an offspeed pitch, could have tied the game with one swing. And Servais said that Gallo was going to be Flexen¡¯s final batter regardless.

¡°He did a really good job that at-bat forcing me to throw the changeup up higher in the zone,¡± Flexen said. ¡°I think he took a lot of good pitches early in that at-bat that I executed really well and he spit on them. And I think we got back in the count with a cutter that he took, and I was missing a little off with the changeup. He forced me up, and I just had the confidence to throw it 3-2 and was able to execute it.¡±

Flexen is slated to make one more start before the second half, next Sunday against the Angels, and it can¡¯t come soon enough. The cerebral right-hander is now 5-2 with a 1.99 ERA in his home confines.