Marsh, Smith fight after Chandimal ton

Steve Smith has become the 26th Australian batsman to reach 4,000 Test runs during his vital knock on day two of the third Test in Colombo.

The current Test skipper is the youngest Australian to reach the milestone, and was also the third-fastest (in terms of innings) to reach the mark among players to have donned the Baggy Green.

Smith entered the ongoing Qantas Tour of Sri Lanka sitting on top of the ICC Test batting rankings, but has struggled to impart any great influence on the contest as his side floundered to a series defeat ahead of the Colombo clash.

Quick Single: Australia fights back on day two

While unable to find his best form in the difficult batting conditions, Smith has still scored more runs than any of his teammates despite an average of 30 in his first two Tests that is well below is career output of 58.41 per innings.

The skipper promoted himself to No.3 in the batting order for the series finale after opener Joe Burns and incumbent first drop Usman Khawaja were omitted from the XI.

Smith walked to the crease at the end of the fourth over after David Warner’s quickfire innings came to an end on 11.

WATCH: Warner hits out, then gets out

Immediately confronted by tweakers from both ends, Smith was eager to use his feet as he searched for a way to overcome the spin threat that had proved so successful in both Pallekele and Galle.

“We’ve got to prove to ourselves that we can play in these conditions,” Smith told reporters ahead of the third and final Test.

“To win the last Test match, that will give us a little bit of confidence.

“We’re going to hopefully play with a little bit more freedom and courage and be willing to take the game on to hopefully get ahead of the game.”

Smith kept ticking along with a glorious lofted drive over the cover boundary a definite highlight, before crunching a short one off Lakshan Sandakan through the off-side and into the rope in front of the hill to move to 29 not out and reach to 4000-run milestone.

The great Ricky Ponting was the previous youngest Australian, with Smith beating 'Punter' by 265 days. While claiming the record among Australian batsmen, Smith comes in at No.14 on the overall list.

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He is the second star batsman to reach the milestone in a matter of days after England's Joe Root did so during the fourth Test against Pakistan at The Oval. Root, aged 25 years and 227 days, is the fourth-youngest batsman ever to achieve the feat.

Smith went on to bring up his 18th Test half century – and just Australia’s second fifty of the series – before going to stumps with his side 1-141 in an unbeaten 120-run stand with recalled opener Shaun Marsh (64 not out).

Fastest Australians to 4,000 Test runs (by innings)

Don Bradman – 48 innings

Matthew Hayden – 77

Steve Smith – 80

Neil Harvey – 80

David Warner – 84

Fastest overall to 4,000 Test runs (by innings)

Don Bradman (AUS) – 48 innings

Herbert Sutcliffe (ENG) – 68

Everton Weekes (WI) – 71

Viv Richards (WI) – 71

Jack Hobbs (ENG) - 75

Youngest Australians to 4,000 Test runs

Steve Smith – 27 years and 73 days old

Ricky Ponting – 27y, 338d

Neil Harvey – 28y, 12d

Don Bradman – 28y, 130d

Allan Border – 28y, 223d

Youngest overall to 4,000 Test runs