Josh Hamilton had two hits and Chris Iannetta hit his third spring homer for Los Angeles.
Skaggs, who is trying to win a spot in the Angels’ rotation, allowed seven hits and two runs in 5¹⁄³ innings.
The Giants got to Skaggs for two runs in the third, but the Angels responded with three runs in the fourth. Hamilton doubled with one out and scored on Raul Ibanez’s single. J.B. Shuck doubled in two runs.
Giants starter Ryan Vogelsong allowed eight hits and four runs in four innings in his sixth appearance of the spring.
Tyler Colvin hit his second spring homer for San Francisco in the eighth.
Vogelsong likely will make the Giants’ rotation coming out of camp, but his ERA remained at 9.00 for the spring.
The right-hander is coming off a rough season, going 4-6 with a 5.73 ERA in 19 starts with the Giants in 2013.
Vogelsong was held out from May 20 through Aug. 9 last season after breaking a bone in his pitching hand.
“I thought my stuff was better today,” he said. “I just need to start making better pitches when I get ahead. I’ll work on that the rest of the way, trying to put guys way.”
Iannetta managed a walk from a 10-pitch at-bat against Vogelsong.
“There were three of four pitches that he just barely ticked,” Vogelsong said. “I’ve got to give him credit.”
Giants manager Bruce Bochy would not say if Vogelsong would begin the season as the fifth starter.
“We won’t talk about what we’ll do if we even talk about it,” Bochy said. “I thought today he was much better. He kept the ball down.”