Australia batted with grim determination through the final day to earn a draw in the third Ashes Test against England on Monday.
The England attack struggled for inspiration and the hosts' best moment was a spectacular one-handed diving catch by James Anderson which dismissed North for 96.
They also had a scare when all-rounder Andrew Flintoff tumbled to the ground after twisting his ankle in his delivery side but he dusted himself down and returned to the attack.
Earlier, Hussey and Watson shared a gritty third-wicket partnership of 85 in the morning session which set the tone for the day.
After resuming on 88 for two, Watson and Hussey survived the first hour with few alarms against the seam attack of Graham Onions and Flintoff.
Watson received a painful blow on the elbow from a Flintoff bouncer but he batted calmly and reached his second half-century of the match in the unfamiliar role of opener.
DROVE LOOSELY
His fifty included nine fours and it was a surprise when, on 53, he drove loosely in James Anderson's first over of the day and gave wicketkeeper Matt Prior a simple catch.
England off-spinner Graeme Swann also bowled an ineffectual spell and Hussey struck several sweet drives through the covers on the way to his second half-century of the series.
He had made 64 when he fell, pushing tentatively at Stuart Broad and offering Prior another simple catch.
Resuming on 172 for four after lunch, Clarke and North mixed watchful defence with crisp attacking strokes to the boundary.
Clarke was dropped on 38 by England captain Andrew Strauss at mid-wicket, a very difficult chance from a full-blooded pull off medium-pacer Ravi Bopara.
Tea was taken at 293 for four and with a draw looking increasingly inevitable North went on the attack in search of his second century of the series.
He took three fours in a row off Bopara but slashed at a wide ball from Broad and Anderson leapt like a salmon to take a stunning catch at gully.
Clarke adopted a more cautious approach in his bid for three figures and he was lucky to survive on 96 when he was caught by Anderson off a Bopara no ball.
But he did reach his 12th Test century soon afterwards with his 14th four and, with Clarke on 103 not out, the two captains immediately agreed to settle for the draw.
Photograph: Reuters