SEATTLE (Interstat) — Emerging from a five-game skid with a resounding statement, the Seattle Mariners completed a four-game sweep of the reeling Houston Astros behind a dominant pitching performance from George Kirby and a historic power display from Josh Naylor, securing a 6-2 victory on Monday evening at T-Mobile Park.

The most important part of the game arrived early and decisively, setting an irreversible tone. After Mariners starter Kirby worked a scoreless top of the first, the heart of the Seattle order immediately pounced on Astros right-hander Mike Burrows. With one out, Cal Raleigh singled and Julio Rodríguez doubled, putting two runners in scoring position. Naylor, mired in a 1-for-15 slump over his previous four games, then announced his return with authority. He drove a Burrows offering to right-center field for a three-run homer, instantly transforming a scoreless game into a 3-0 Seattle lead before many of the 18,648 in attendance had settled into their seats.

That first-inning blast was merely a prelude. In the third inning, after Raleigh led off with another single, Naylor struck again. He launched his second home run of the afternoon, a two-run shot to center field, extending the Mariners’ advantage to 5-0. The five RBIs marked his seventh career game with five or more driven in, and the two-homer game was his first of the young season, single-handedly building an insurmountable cushion.

Kirby, the winning pitcher, was the beneficiary of that offensive eruption and made it stand up with precision. He efficiently managed the Houston lineup over 7 2/3 innings, scattering seven hits and allowing two earned runs. He walked none and struck out six, requiring just 89 pitches to navigate into the eighth inning. His command allowed the Mariners to rest a bullpen that had been taxed during their recent losing streak.

The Astros, who have now lost eight consecutive games—their longest slide since a 15-game skid to end the 2013 season—showed a flicker of life in the fifth inning. Cam Smith and Taylor Trammell singled to open the frame. Yainer Diaz followed with an RBI single to center, plating Smith. Nick Allen then grounded into a double play, which allowed Trammell to score but effectively killed a potential larger rally. That sequence accounted for Houston’s only runs, trimming the deficit to 5-2.

Seattle answered immediately in the bottom of the fifth, however, to quell any notion of a comeback. Rodríguez singled, stole second, and scored on an RBI single from Luke Raley, who finished the afternoon 3 for 4. That run restored the four-run margin at 6-2.

From there, Kirby and the Seattle bullpen slammed the door. After Kirby allowed a two-out single in the eighth, reliever Matt Brash entered and needed just one pitch to induce an inning-ending lineout from Isaac Paredes. Cole Wilcox then worked a perfect ninth inning to seal the victory.

The loss dropped Houston to 6-11 on the season, firmly in last place in the American League West. Burrows, the losing pitcher, was tagged for six runs on 11 hits over six innings of work, falling to 1-3. In contrast, the Mariners climbed back to .500 at 8-9, having exorcised the frustrations of their recent slide entirely at the expense of their division rivals.

Offensively for Seattle, Rodríguez and Brendan Donovan each added two hits to support Naylor’s heroics. For Houston, Diaz’s RBI single was a highlight in a seven-hit team effort that consistently failed to capitalize with runners on base, going 1 for 4 with runners in scoring position and grounding into two double plays.

The result defied the pregame projection from Interstat’s game simulator, which had forecast a 4-2 Houston victory, though it aligned with the same service’s ELO probability, which gave Seattle a 58.1% chance to win. The Mariners covered the spread as 1.5-run favorites, and the combined eight total runs went under the posted over/under of 7.5.

The Mariners will look to carry this momentum on the road as they open a three-game series against the San Diego Padres on Tuesday. The Astros, desperate to stop their lengthy slide, return home to Houston to begin a three-game set with the Colorado Rockies, also on Tuesday.