PERTH, Feb 27 AAP - Mercurial Michael Slater showed why he was once one of the most feared batsman in the world with a punishing 204 against Western Australia today.

The former Test player and Greg Mail's (90) opening stand of 263 put NSW in a powerful position at stumps on day one of a Pura Cup cricket match in Perth.

After being sent in, NSW was 3-353 with Simon Katich (30no) and Steve Waugh (11no) at the crease with WA captain Justin Langer's decision to bowl first backfiring badly.

It didn't appear such a bad choice with the pitch having a strong green tinge to it - but the Blues batsmen made it look like a road.

Langer could not have expected Slater, who had scored just 83 runs from his last seven digs in the four-day competition, to be back to his imperious best.

The 33-year-old's 204 came off 238 balls including 26 fours and five sixes in a typically dashing innings in just over five hours at the WACA Ground.

It was a truly memorable knock on the same ground in which he recorded his highest Test score of 219 in December 1995 against Sri Lanka.

He brought up his double century by punching a ball through midwicket for a single from spin bowler Beau Casson.

Slater took off his helmet and saluted the small crowd in a rare show of emotion today for a man who has worn his heart on his sleeve during his rollercoaster career.

But he fell shortly after, bowled around his legs by Jo Angel after Slater drifted onto the off side.

"There has been a couple of games where I haven't set the world alight but you have to hang in there," Slater said.

"Today was a really enjoyable day particularly with the state of affairs with the competition, with both teams needing to win the last two games to be a chance of making the Pura Cup final.

"We are in the box seat now, which is nice."

Slater and Mail fell 56 runs short of the record NSW opening partnership of 319 set by Rick McCosker and John Dyson in 1980/81 against WA in Sydney.

The stand rubbed salt into the wound for WA which suffered a humiliating ING Cup final loss to the Blues on Sunday and all but killed the Warriors' slim hopes of making the four-day final.

But their success was against a WA attack badly missing spearhead Brad Williams who was ruled out just before the start of play with an elbow injury.

Matthew Nicholson was called up after the former Victorian's elbow ballooned overnight after it was struck by a a ball at a training session yesterday.

It continued WA's injury woes with young WA batsman Shaun Marsh's ongoing groin complaint sidelining him for the four-day match.

WA finally had something to be happy about in the last session of the day with Mail failing to deliver his third first class century, bunting a simple catch to Chris Rogers at short cover.

But the Warriors should have had former teammate Simon Katich back in the pavilion for one however Callum Thorp grassed a simple chance after the ball bobbed up kindly out of teammate Rogers' hands.

Slater then fell to Angel before Nicholson bowled Michael Clarke (9) late in the day.