Lyons, a 2010 ninth-round pick out of Oklahoma State, worked out of the bullpen before starting the second game of a twinbill on June 27.
"I did both in college but more starting than relieving," Lyons said. "I'm pretty comfortable doing either."
After being hit hard in his first two starts -- he surrendered eight runs on 11 hits over 8 2/3 frames -- Lyons shone against the Blue Jays on Sunday afternoon. He retired the first five batters before issuing a two-out walk to Kevin Ahrens in the second.
Lyons (3-3) fanned the first two batters in the third, but Brad McElroy reached on a throwing error by third baseman Niko Vasquez and A.J. Jimenez walked to put a runner in scoring position. Lyons got Sean Ochinko to fly out to left, ending the threat.
Ryan Goins collected Dunedin's lone hit with a two-out single to left in the fourth, but Lyons retired his final four hitters. The 23-year-old left-hander went a career-high five innings and walked three while matching a personal best with five strikeouts. He did not allow a runner to reach third.
"I ended up throwing 83 pitches, but I still felt like I had something left in the tank," he said. "I was mainly working off my fastball, with the curve to keep hitters off-balance, but everything was working well."
The Cardinals turned to Swagerty to finish out the gem. After making 12 starts at Class A Quad Cities and Palm Beach, the 2010 second-round pick was working just his fifth game as a reliever.
Swagerty hit Brian Van Kirk with two outs in the sixth and walked Ivan Contreras with two down in the seventh but was otherwise perfect in recording his first professional save. He struck out one and has allowed just two hits over six scoreless innings as a reliever.
Palm Beach scored the game's lone run in the second. Rainel Rosario hit a leadof double to left, moved to third on Vasquez's groundout and scored on a sacrifice fly by Robert Stock.
Dustin McGowan (0-2) took the loss for Dunedin, allowing one run on two hits in two innings. It was his third outing since returning from a series of arm surgeries that kept him out of baseball since going 6-7 in 19 starts for Toronto in 2008.