(BSS/AFP) - Steve Smith and Cameron Green half-centuries pushed Australia into the ascendancy with a lead of 254 runs at stumps on the third day of the second Test against the West Indies at the National Cricket Stadium in Grenada on Saturday.

Holding a 1-0 lead in the three-match series following a 159-run victory in the first Test in Barbados, the tourists have three wickets in hand as they sit on 221-7 going into the fourth day of what has so far been a low-scoring duel.

Smith`s innings of 71, his 43rd Test half-century, reflected his awareness of the state of the match as the day progressed.

Cautious at first when he came to the crease with his side again in early trouble at 28 for three in the first session, Smith unfurled more of the trademark shots from his considerable repertoire in productive partnerships with Green and then the always aggressive Travis Head.

He looked well set to coast to a 37th Test hundred after tea only to be undone by Justin Greaves, the seam bowling all-rounder trapping Smith lbw to end an innings that spanned 119 deliveries and included one six and seven fours.

His 93-run fourth-wicket partnership with Green was pivotal in the visitors tilting the balance of play in their favour.

"It`s a tricky surface, a bit up and down, a bit of seam movement, so for this innings I decided to bat on middle (stump) and try and be a bit more still to negate lbw as much as possible," Smith said.

"And then anything loose try to cash in on it. You`ve got to try to put the bad balls away to put the pressure back on the bowlers."

- `In a nice spot` -
For the former captain, the state of the pitch plus effective use of the new ball will give Australia the advantage going into the final innings of the match.

"We`re in a nice spot. I don`t think the wicket is going to get any better to bat," he said.

"I think the new ball will be pretty critical for us when we get that opportunity but hopefully we can first get up to (a lead of) 300."

Green, whose previous three innings in this series in the vital number three position have raised questions about his suitability for the role, displayed commendable discipline and application in working his way to a seventh Test fifty.

All his good work was undone though by the vagaries of this two-paced pitch as he was bowled off the inside-edge by Shamar Joseph for 52 halfway through the afternoon period.

His watchful innings occupied 123 balls during which he stroked five fours.

Head was also a victim of uneven bounce, although the persistent pace and accuracy of Shamar Joseph contributed to him being bowled for 39.

Alex Carey (26 not out) again eked out important runs for Australia at the end of the day, and resumes on the fourth day in partnership with captain Pat Cummins.

Earlier, nightwatchman Nathan Lyon`s demise lifted West Indies spirits higher after a strong finish to the second day when a Jayden Seales double-strike reduced Australia to 12 for two at stumps.

Lyon offered a catch high to John Campbell at second slip off the bowling of Alzarri Joseph having done his job the previous evening in protecting the next man in, Smith, from having to negotiate a tricky few minutes to the close.

After missing the first Test through injury and then falling cheaply in the first innings on Thursday, Smith was clearly intent on lengthy occupation of the crease second time around.