Smith ton denies England face-saving Ashes win

Australia captain Steve Smith tormented England with another century as the fourth Ashes Test ended in a frustrating draw for Joe Root's side on a lifeless Melbourne Cricket Ground pitch on Saturday.

Smith marched off unbeaten after a 275-ball knock of 102, having nudged Australia to 263 for four and a lead of 99 runs before the captains called it off midway through the final session.

Number six batsman Mitchell Marsh was as stubborn as his captain, scoring 29 from 166 balls to protect his wicket through the last two sessions.

The unyielding drop-in pitch may have been England's biggest obstacle, however, refusing to offer their bowlers any encouragement in terms of pace, movement or turn.

"I don’t think it’s good for anyone," Smith told reporters of the wicket after his third century of the series.

"There was absolutely nothing in it for the bowlers.

"I’m enjoying (batting), shame we had to call it off in the last hour, I could have had another hour out there."

With Man-of-the-Match Alastair Cook finding form with an unbeaten 244, the tourists can perhaps claim a moral victory after their batsmen built a first-innings lead of 164 runs.

But they will still head into the fifth and final Test 3-0 down in the series and desperate for a face-saving win at the Sydney Cricket Ground.

While stopping short of criticising the pitch, Root said his side had performed so well in dismissing the hosts for 327 in their first innings.

"On a very unresponsive wicket, to perform how we did on that first and second day with the ball was outstanding," he said.

"Disappointed that we couldn't quite crack it open today but we tried out absolutely everything."

Smith, having scored an unbeaten 141 in Brisbane and 239 in Perth, came to the crease before lunch on day four, his team vulnerable at 65 for two.

He had to dig them out of another rough patch when England grabbed two late wickets early on Saturday to leave Australia wobbling at 178 for four.

The skipper brought up his century by cutting part-time legspinner Dawid Malan for a single, but there was no fist-pump or roar of celebration as in the previous matches.

The 28-year-old simply raised his bat dutifully to the sparse fifth day crowd before battening down again.