Dan Marsh stood up at a crucial time to collect two first-innings points for Tasmania, who had to fight off a superb performance from Ryan Harris at Adelaide Oval. Harris captured a career-best 7 for 108, but his batting team-mates failed to offer the necessary help and they ended the third day on 6 for 196.
The home team has a lead of 157 and the Tigers will be desperate to clean up the last four batsman on the final morning of what could be a tense tussle. Brett Geeves continued Tasmania's dominance when he picked up the first three wickets, but the Redbacks recovered through useful contributions from Daniel Christian and Callum Ferguson.
Christian was nearing his second half-century in consecutive games when he was caught by Marsh for 47 off Chris Duval, the former South Australia bowler. Ferguson reached his fifty but fell soon after when caught-and-bowled by Geeves for 54. The Redbacks' troubles had already increased with the loss of Shane Deitz for 8, but Graham Manou, the captain, prevented any further damage and was 22 not out at stumps.
Tasmania started the day at 5 for 228 and Marsh cautiously navigated them past the home team's 344 with help from Tim Paine, who picked up 57. Paine fell to Harris 16 runs before the total was overhauled, but Marsh stayed until his off stump was taken by Harris.
He was 109 and the century, which contained 11 fours from 192 balls, was the third of a fine season. Harris' final wicket came when he bowled Geeves for 0 and he continued an excellent day by being 6 not out at the close.