The result ended the Redbacks' hopes for the summer.

Travis Head hit a sparkling 145 from 167 balls to have the Tigers on the back foot as they defended 330, only for the SA skipper to fall with victory in sight.

The Redbacks, having made the final the past two seasons, will enter next week's final round in bottom place.

Tasmania, on the other hand, are flying high and will take a narrow lead into their winner-takes-all match against Victoria in Hobart starting on Wednesday.

"Four wins is probably a little bit above expectation to where we thought we would be at this stage, so we are really happy with that," Tasmania coach Adam Griffith said.

"The confidence is good and they are enjoying their cricket which is probably the biggest thing, and that was something that was probably [previously] lacking in the group."

SA slipped to 4-69 early on the final day, before Head led a remarkable revival, aided by Tom Cooper (38), Joe Mennie (29) and Nick Winter (25).

Sam Rainbird (3-86) took the key wicket of Head just after tea, while Jackson Bird returned the best figures for Tasmania, collecting 4-64 from 24.1 overs.

Ironically, Bird was replaced in Australia's touring squad by the Redbacks' key wicket taker Chadd Sayers.

Bird took six wickets in his first match back from a hamstring injury and shapes as a key figure for the Tigers' Shield run-in.

"It's pretty handy having a Test cricketer to run in and take those wickets," Griffith said.

"He was really good towards the end and bowled well.

"He was a bit rusty with the hamstring injury, so he will take some confidence from that game."

While happy with his seventh first class century, Head lamented both the narrow defeat and the team's inconsistent form this season.

"To get where we did today was great but I'm pretty disappointed personally that I couldn't give us the opportunity to win the game," he said.

"We have had some close games where we haven't quite been able to get over the line but we have been pretty inconsistent at times, so it has been a pretty up and down season."

Australian Associated Press