MLB Game Summary - San Diego at Seattle

Peoria, AZ (SportsNetwork.com) - Justin Upton homered in his Padres spring training debut, but San Diego fell to the Seattle Mariners 4-3 in 10 innings on Wednesday.

Upton, acquired from Atlanta in December, hit a solo homer to center field in the seventh inning for San Diego's first run and the Padres tied the score in the ninth on a Mariners error.

But Tyler Marlette stroked a pinch-hit single for Seattle in the 10th inning and scored the winning run on a single by Patrick Kivlehan and an error by right fielder Rymer Liriano.