Cleveland Guardians at Seattle Mariners: Final Score & Recap

The Seattle Mariners opened their 2026 home slate with a dominant 8-0 shutout of the Cleveland Guardians on March 29 at T-Mobile Park. Cleveland managed just two hits and committed one error across nine innings, while Seattle's offense came to life in the middle frames to put the game away early. The DiamondIQ model entered the evening giving Seattle a 54 percent chance of winning and watched that figure climb to 100 percent by the final out.

The decisive moment came in the bottom of the fourth inning, when Brendan Donovan connected on a home run off Guardians starter Slade Cecconi that swung win probability 26.4 percentage points in Seattle's favor, the single largest play of the game by a wide margin. Leo Rivas followed that blast with a single that added another 7.7 percentage points, and the Mariners tacked on two more runs in the fifth, aided by a Randy Arozarena double off Cecconi that carried a 3.8 percent win-probability swing. Cecconi was the focal point of Seattle's damage all night, surrendering the bulk of the Mariners' production across the middle innings.

Donovan finished as the game's standout performer, posting a cumulative WPA of plus-31.0 percent and a RE24 of plus-3.9, largely on the strength of his fourth-inning home run and a hit by pitch in the third that contributed another 3.8 percentage points. On the pitching side, Emerson Hancock was the clear beneficiary, earning a plus-18.4 percent WPA as he held Cleveland's offense in check and preserved Seattle's commanding lead. Rivas and Cole Young also contributed positively at plus-4.9 and plus-2.6 percent WPA, respectively, as the Mariners spread their production across the lineup in a clean, efficient opening-day victory.