The 27-year-old relieved starter Daisuke Matsuzaka in the second inning, inheriting a 4-0 deficit and a bases-loaded jam. Facing Cardinals cleanup hitter Rick Ankiel, Smith threw three offspeed pitches and earned his first strikeout against the first batter he faced.
"I was telling my family, 'It was like you have a volume on your car and it's at four, and then you throw another strike and it's at six, then the next pitch is a strikeout and it goes from six to 12,'" Smith said of the Fenway Park crowd's intensity despite the deficit. "You felt a wave through the stands. You see it in movies -- just like a big explosion. It was crazy. It was unbelievable."
Smith went four innings in the debut, giving up just three hits, striking out three and being charged with one earned run. That run, however, came as part of a grand slam he served up to Troy Glaus immediately after the Ankiel strikeout. The three runners on base were charged to Matsuzaka.
"Watching all the highlights, it was a pretty bad pitch," Smith said. "Obviously, I can't take anything back, and I don't think I would. I got a lot of positives out of that outing."
Smith said he was happy the outing could happen in Boston as opposed to on the road. Smith was called up from Triple-A Pawtucket on Tuesday, taking the roster spot of Bartolo Colon, who went on the 15-day disabled list with a sore back. That meant Smith spent time with the team during the recent trip to Philadelphia.
He said although he was itching to get the chance to pitch, it was nice to make his first appearance at home.
"All the electricity in the stands," Smith said. "To be able to jar it all up and start pitching -- I was like, 'How did I do that?' "
It was a special occurrence for manager Terry Francona, too. He said he was anxious to get Smith on the hill.
"It's hard not to root for guys like Smitty," Francona said. "If you see him in the clubhouse, he loves to pitch. He's a polite kid. So it was fun to watch him do his thing."
Granted, Francona admits the outing -- albeit memorable and successful for the young righty -- would be a little more sweet had the Sox been able to snag a win in the process. But even Francona was taken aback by the support Smith received when striking out batters in the midst of a lopsided affair.
"I've never seen a place like this," Francona said. "We're down 8-0, he throws a strikeout, and the fans react. They know. It's a special place."
Smith wasn't surprised. Given his background with the Red Sox organization, he said this was the type of support he's come to expect out of the team's fans.
"They're behind you 100 percent," he said. "It's a family atmosphere where they feel like they know you, which is great. They can see this game, Double-A and Triple-A maybe within a weekend. And if you don't have success, they'll get on you just like a family would."
Mark Remme is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.