Yacaman finished a career-best second after notching his first front-row start in Firestone Indy Lights, while Garcia moved back into third place in the championship after finishing fourth despite starting from the back in the 115-lap race.
"This was the hardest frigging race I've ever driven, so close on so many occasions," said Yacaman, who last finished on the podium at Toronto in 2010. "Between Bryan (Clauson) and I, a fly couldn't be able to be there. We were running so close."
Yacaman also had to survive an early race incident with pole-winner Esteban Guerrieri ,which nearly sent both cars into the Turn 3 SAFER Barrier. Both cars were able to continue, though Guerrieri was forced to retire with damage several laps later.
"I was either going to go for the lead or go for the wall," Yacaman said. "I told everyone on the team I wasn't going to lift. You know, I didn't lift. That's what happened. I'm sure next time he'll give me a little bit more space, maybe a foot or two instead of just chopping me right off. He knows I'm not afraid of taking both of us out. It's how it works. You know, you've got to earn your respect. That's what I did.
"Yeah, it was a lot of risk, but hey, it paid off. I'm pretty sure not even just on ovals but also on road courses he's going to know I'm there and I'm not going to lift, and we're not here to make friends, we're not here to be careful. This is racing, and like they say, rubbing is racing, right?"
Garcia, meanwhile, steadily worked his way to the front after a fuel pump issue forced the No. 22 Xtreme Coil Drilling car to start 12th.
"We knew we had a car capable of being at the top but (in qualifying) we had a fuel pump problem," Garcia said. "My team was telling me to relax and go faster and faster each lap. At the end I was catching people and overtaking."
Garcia, who scored his first win at Barber, was happy to reward his team with another strong result, one that helped bring his team back into title contention.
"I'm really happy for the team after they worked so late (June 24)," he said. "I have to thank everyone for all the hard work they did. I'm really happy because we are third in the championship now."
Yacaman also credited his crew, working under team owner Mark Moore as the team's engineer/strategist for strong races at Iowa and Milwaukee, where he finished fifth.
"It was a pretty tight finish, and I really want to thank Mark (Moore)," Yacaman said. "We worked so hard. We've had a strong car so many times, but it's really good to capitalize on that equipment he's given me. We've just had so much bad luck at Indy, Barber. Long Beach was all right, but we want more, we want podiums, we want race wins. I'm working really hard with the team, and here we are, first podium, and I'm going to keep working just as hard to keep them coming."