ATLANTA -- Just as the Mariners’ offense seemingly took a big step forward with a big win on Saturday, they trudged one step back in Sunday’s series finale at Truist Park. And for the third time this season, they spoiled another stellar start from George Kirby.

Seattle had just three hits in a 3-2 loss to the Braves on a day in which Kirby cleared the seventh inning and made just one notable mistake, which was all the more costly. The Mariners have now lost three of his starts in which he’s surrendered just three runs or fewer, including a complete game in Philadelphia on April 27.

“I thought I did my job out there,” Kirby said. “I felt good today. Sometimes, you don't win them.”

Kirby’s outlying blemish was a middle-away fastball that Travis d’Arnaud ambushed for a solo homer to lead off the sixth inning. The other runs were manufactured via a double from Matt Olson on a low-and-in curveball -- perhaps more in Olson’s zone than desired -- and a two-out walk to Olson in the third that led to him scoring after d’Arnaud and Eddie Rosario impressively found the edge of the barrel in two-strike counts to keep Atlanta’s rally alive.

Even d’Arnaud felt he benefited from good fortune on the homer, saying, “I just got lucky and it hit my bat. I just tried to get ready to hit, and I blinked and hit it on the barrel."

And that was it. Kirby threw 88 pitches and saw a sizable uptick throughout his repertoire, with his sinker (+1.5 mph) and four-seamer (+1.7 mph) jumping in velocity for the second straight start. The heaters accounted for all of his six strikeouts.

“Awesome outing by George again,” Mariners manager Scott Servais said. “The type of season he's putting together is pretty remarkable and fun to watch, just watching him grow and get better every time out there.”

Kirby is putting together a strong All-Star bid with just 51 days before the Midsummer Classic. But at this rate, he might be their lone representative, which would be a disappointment given that it will be held at T-Mobile Park. That’s largely because Seattle’s lineup -- particularly its top-end talent -- has struggled with consistency.

The Mariners’ lone runs on Sunday came via homers, which they’ve been lacking compared to last season. But they came in sequences with no one on base. Jarred Kelenic crushed a Statcast-projected 394-foot home run to lead off the second inning, and Jose Caballero lifted a 391-foot blast in the eighth for the first of his career. Caballero also had three stolen bases, joining Mike Cameron on May 16, 2002, as the lone Mariners to have a homer and three steals in a game.

Caballero’s 102.9 mph blast and Kelenic’s 100.6 mph drive were among eight balls that the Mariners ripped with a triple-digit exit velocity, but five went for outs, underscoring some offensive frustration. But the bats also were again susceptible to spin, this time from Atlanta starter Jared Shuster, who went six innings and gave up just one hit and one walk.

Seattle, which entered the day hitting .185 against sliders and sweepers (third worst in MLB), went 0-for-6 with three strikeouts against Shuster’s breaking ball on Sunday. It’s been a notable challenge dating back to last season.

“It's hard to overcome when you don't put the ball in play,” Servais said. “Whether it's, you know, more changeups than we were expecting or more life on the fastball, whatever, at some point you’ve got to cut down your swing and get the ball in play.”

There were positives on this 4-5 road trip, but also maybe some wins left on the table.

The Mariners scored only two runs on Friday and Sunday, which is incredibly challenging to produce a win with against juggernaut Atlanta, especially in its home park. And aside from tough starts from Luis Castillo and Marco Gonazles in Boston, their starting pitchers put them in position to win in the seven other games.

It’s the stage of the season, too, where significant external changes aren’t really out there, not until the Trade Deadline draws nearer, and it is over two months away. Minor League reinforcements are also thin. The group that the Mariners will need to figure things out is here -- and heading home for a 10-game homestand with no off-day beginning Monday.