Put simply, Fifita was dominant up front in the second half after he came in to replace Soliai.
In addition to the sack, which produced a 10-yard loss, Fifita's five tackles also included a stop for no gain of Alvin Pearman and a stop for a 2-yard loss of Derrick Wimbush.
Not surprisingly, Fifita called it a night when everything "went good."
Fifita was signed by the Dolphins in January and was sent to play in NFL Europa, where he helped Frankfurt reach the World Bowl.
"It kept me in shape," Fifita said of playing in Germany. "It was a really good experience. I learned how to play football again. It felt good just to get back on the field."
Fifita was out of football last year after being waived by the Dolphins in late August.
The 6-foot, 320-pound Fifita had been signed as a college rookie free agent after he played at Utah, where he lined up on defense next to Soliai.
Ironically, the drafting of Soliai severely hurt Fifita's chances of making the roster this summer because the Dolphins aren't likely to keep more than one backup nose tackle behind Keith Traylor, and they're obviously high on Soliai's potential.
But the truth is Soliai was pretty much invisible against Jacksonville despite playing the entire first half.
Soliai was credited with one tackle against the Jags and seemed to be controlled most of the time.
Of course, Soliai was going against Jacksonville's first-team offensive line, while Fifita was operating against mostly backups.
But regardless, it clearly was the perfect way to start the preseason for Fifita.
"My goal is just to go out and stay positive," he said. "I know it's going to be hard because there's a lot of guys, but I'm going to do my best."
As far as competing against Soliai, Fifita says, "It's not like we're competing against each other, I'm competing against myself."
After the first preseason, Fifita can say he's winning whatever battle it is he's engaged in.