"To get the first one out of the way is very big," he said. "Hopefully there are many more to come."
Arenado homers as Rockies outlast Giants, 12-11
Steven Duggar and Brandon Crawford each had two-run singles, pinch-hitter Tyler Austin added a two-run triple and Joe Panik had three hits, including an RBI single.
Williamson homers in return, Giants beat Rockies 14-4