Sonnanstine struck out 10, including seven straight at one point, as Tampa Bay beat the Florida Marlins 9-4 on Sunday.
Brendan Harris had a career-high five RBI and Raul Casanova homered for the second straight day for the Devil Rays, who went 4-2 on their first winning road trip of six or more games since July 14-20, 2005.
Sonnanstine (1-0) allowed two runs and seven hits, walking none in seven innings in his second career start. He struck out seven straight, one shy of the AL record of eight. That mark has been achieved six times, most recently by Blake Stein of Kansas City on June 17, 2001.
"I didn't even know that until you guys just told me," Sonnanstine said. "It's just staying ahead in the count and pounding the strike zone -- don't just let them get to first by walking."
"I didn't know he was going for the record," catcher Casanova said. "I would have tried harder for the strikeout."
Unlike Casanova, other Tampa Bay players were left to watch Sonnanstine.
"It was nice, because it wasn't like they were six-pitch strikeouts. They were usually three, four, five pitches," Harris said. "But you're getting balls when they're throwing it around (following strikeouts), so it's like your getting some action."
Sonnanstine, a 6-foot-3 right-hander who bats left-handed, had his first two career hits and first career RBI despite not having swung at bat in a game since his junior year of high school. He was just as impressive with pitch location and his ability to use different arm angles.
"He was changing speeds and almost looked like a little younger version of El Duque," said Marlins manager Fredi Gonzalez, referring to New York Mets right-hander Orlando Hernandez.
"It's good for the industry to see a guy pitch well who pays attention to deception and knows what he's doing out there," Devil Rays manager Joe Maddon said. "A lot of times guys like that fall through the cracks."
Rick Vanden Hurk (1-2) surrendered five runs and six hits in five innings. He walked three -- one intentionally -- and struck out six. In his previous start, he took a no-hitter into the seventh.
Jeremy Hermida and Miguel Olivo hit solo home runs for Florida, which failed to get back to .500. The Marlins struck out 34 times in the three-game series to run their major-league leading total to 550 in 64 games.
"We're still leading the league in runs," Dan Uggla said. "That's part of the game, that comes with it. We're an aggressive, free-swinging team."
With two out in the third, Sonnanstine singled to left before Akinori Iwamura doubled to right-center. Harris fell behind 0-2 before sending a payoff pitch into the right-center field seats for his sixth home run, giving Tampa Bay a 3-0 lead.
Tampa Bay scored twice in the fourth to take a 5-0 lead. Delmon Young's run-scoring double and Sonnanstine's RBI single produced the runs.
Hermida's 433-foot home run to right in the fifth made the score 5-1. It was Hermida's fifth homer.
Casanova hit a 431-foot solo shot to dead center in the sixth to make it 6-1.
Olivo made the score 6-2 when he homered to left with one out in the seventh.
- Sunday's crowd of 11,525 meant a total of 45,234 fans saw the three-game series.
- Sonnanstine's seven straight strikeouts set a team record. Scott Kazmir struck out six straight against Toronto on April 8.
- Sonnanstine gave up six earned runs in seven innings during his major league debut at Toronto on June 6. He hasn't walked a batter in 14 innings.
- Sonnanstine's 29 wins the previous two seasons were the most among all minor league pitchers.