Lopez, the D-backs' new leadoff hitter after signing a $3.5 million free agent deal at the winter meetings, homered to lead off the last of the first inning, becoming the first player in franchise history to homer in the first at-bat of the season.

"It's there," Lopez said of his power. "I'm not trying to hit home runs. If it happens, it happens. As a leadoff guy, I just try to get on base as much as I can."

Lopez is the fourth D-back to homer from both sides of the plate in the same game. Clark previously did it in 2005, also against Colorado. Alex Cintron (2004) and Orlando Hudson (2006) are the others.

"Felipe was the key," Clark said.

Clark, who started with San Diego last season before being acquired by the D-backs at the All-Star break, hit three home runs in 151 combined at-bats last season. He got the start to give the team another left-handed bat in the lineup against Colorado right-hander Aaron Cook.

DIAMONDBACKS 9, ROCKIES 8: 3B Chad Tracy hit the last of the D-backs' five home runs leading off the seventh inning to break an 8-8 tie. Switch-hitting 2B Felipe Lopez and 1B Tony Clark hit two home runs apiece, becoming the first teammates in major league history to homer from each side of the plate on opening day. Lopez's blast in the first inning was the first leadoff homer on opening day in franchise history.