Juan Soto walked in his first plate appearance as a Padre on Wednesday, and Josh Bell walked in his first plate appearance for San Diego.However, Brandon Drury hit the first pitch he saw as a Padre for a grand slam, leading San Diego to a 9-1 victory over the visiting Colorado Rockies.Manny Machado and Jake Cronenworth also homered for the Padres, who won their fifth straight game. San Diego has won the first four contests in the five-game series that concludes Thursday afternoon. Colorado has lost five in a row.Padres starter Blake Snell (4-5) allowed one run on four hits and no walks over six innings to earn his fourth straight win. Snell, who struck out nine, has received 19 runs of support in his last two starts after getting only 29 runs of support in his first 11 starts of the season.With Soto, Bell and Drury all making their team debuts, the Padres scored five times in the first inning off Rockies starter Chad Kuhl (6-7).Soto drew a one-out walk to start the rally. Machado followed with a double ahead of Bell’s walk that loaded the bases. Cronenworth was hit by a pitch to produce the first run.Drury then drove the first pitch he saw from Kuhl into the left field stands to make it 5-0. It marked the first time in Padres history that a player hit a grand slam in his first plate appearance. The homer was No. 21 on the season for Drury, who was acquired from the Cincinnati Reds on Tuesday.Soto and Bell both came in a trade with the Washington Nationals.