"It was a huge relief," LaFromboise said of the initial out. "I was just trying not to walk him, to be honest. The adrenaline was getting to me, but I was just trying to throw strikes. To get the first one was unbelievable.
"You can't really exhale, because the next guy was Pena, but the whole goal is to get lefties out and prove I can do it. I think I took a first step in that."
LaFromboise was an eighth-round Draft pick of the Mariners in 2008 and reached Triple-A Tacoma at midseason last year, going 5-2 with a 1.59 ERA in 27 appearances. How about getting to the Majors at this point in his career?
"It's a huge dream," LaFromboise said. "I've been dreaming about this since I was 5. And my parents know it, so that's why it made it so amazing to tell them."
LaFromboise's father, a tire salesman in Los Angeles, tried to attend all his games growing up and flew in Thursday and will be at the rest of the Rangers series this weekend. That naturally was his first phone call after Wednesday's debut, once his heart stopped racing.
"I walked around the clubhouse for an hour," he said, "then I got back to my room and was walking back and forth in there for about another hour, talking to my dad and just saying, 'Wow, I did it.'"
Manager Eric Wedge liked what he saw from the initial outing.
"Real impressive," said Wedge. "He throws the first couple balls, then he comes right back with the fastball down at the knees for a strike and just kept going from there. Like I've said so many times, you're just not sure what you're going to get with a first time out, but he was very impressive."
Greg Johns is a reporter for MLB.com. Follow him on Twitter @GregJohnsMLB as well as his Mariners Musings blog. This story was not subject to the approval of Major League Baseball or its clubs.