Paxton threw 5 1/3 scoreless innings in his first game since May 2 due to a strained forearm. The 28-year-old southpaw allowed just three hits with no walks and six strikeouts in a 74-pitch outing to improve to 4-0 with a 1.26 ERA in seven starts.
Rockies rookie Antonio Senzatela suffered his first loss in five weeks as he allowed five hits and four runs over five innings to fall to 7-2 with a 3.49 ERA. Catcher Tony Wolters had two of Colorado's four hits.
The loss left the Rockies a half-game back of the Dodgers in the National League West at 33-22 as they dropped their third straight to Seattle after opening the week with two losses at Coors Field in the Interleague series.