Continuing from 18 for no-loss at Lunch, Mitchell Johnson got his first wicket of the match when dismissed opener Tilakaratne Dilshan for just five runs, leaving Sri Lanka at 24 for one.
Karunaratne was then joined by Jayawardene and the duo slowly but steadily built the innings to reduce the deficit to just eight runs before going for Tea break.
Karunaratne scored a brisk half-century and is batting on 83 off just 99 deliveries while skipper Jayawardene is giving him a good stand with 38 runs to his name. The duo added 106 runs for the third wicket.
Brief Scores: Sri Lanka 294 and 225 for 7 (Dimuth Karunaratne 85, Mahela Jayawardene 60; Mitchell Johnson 2 for 19) lead Australia 432 for 9 dec. (Phil Hughes 87, David Warner 85, Matthew Wade 102*, Michael Clarke 50; Rangana Herath 4 for 95) by 87 runs