"I got the first homer out of the way," Williams said. "It was a curve. (Valbuena) had to go down to get it and he did."
Williams is familiar with his status, somewhere in between that of a reliever and a starter. Angels manager Mike Scioscia said both Williams and right-hander Garrett Richards, among others in the same situation, would be stretched out as starters this spring.
"Every year I'm going to have to fight for a roster spot," Williams said. "The number one key is to help the team in any way possible."
Williams yielded one run and two hits over two innings, with a walk and a strikeout. Cubs starter Travis Wood also went two innings, giving up two runs and one hit.
"I hate leadoff walks," said Wood, who was 6-13 with a 4.27 ERA in 26 starts for the Cubs last season. "It's nice to get that first one out of the way. ... Everybody's competing for the same spot. It's going to be fun throughout the rest of camp."
Brett Jackson tripled twice for the Cubs, and Valbuena got off to a great start in his bid to win more playing time.
Valbuena, one of three players in the running for the team's starting third base position, homered to the opposite field off Williams in the second inning. Valbuena also went deep in an intrasquad game Friday.
Valbuena hit .219 with four homers and 28 RBIs in 265 at-bats for the Cubs last season. He's currently the only one of the three third base candidates who is active, because Ian Stewart and Josh Vitters are out of action for at least two weeks with strained quads.
Williams went 6-8 with a 4.58 ERA in 32 games (15 starts) for the Angels in 2012. He opened the season as the team's fifth starter but was later moved to the bullpen.
Scioscia was satisfied with Williams' outing Saturday.
"His stuff looked good," Scioscia said. "The pitches they got to him, he missed a couple of locations and they hit it."
Hank Conger, fighting for the Angels' backup catcher spot, drove in a run with a groundout and added a line-drive single.
Stewart has a moderate left quadriceps strain and is expected to miss two weeks. Cubs manager Dale Sveum said he would expect Stewart back "in two weeks at the earliest, but realistically three weeks." Sveum said the same about Vitters but added that both should be back in time to compete for the third base job. "There are a lot of games left," Sveum said. "They'll get enough at-bats." ... Sveum sided with his counterpart, Scioscia, who expressed disappointment that he had to open Cactus League play with a split-squad game. "It makes it difficult," Sveum said. "It is tough to manage that." Because there are 15 teams each in Arizona and Florida, MLB requires at least one split-squad game per day so that all teams can play, with weekends taking precedent.