You just can’t keep Cam Green out of the game.

A few hours after top-scoring with his maiden List-A century, the rising West Aussie star produced a piece of game-changing magic in the field to get rid of dangerous South Australian captain Travis Head.

The dismissal sparked a horror collapse of 9-76 as WA got their Marsh One-Day Cup defence underway with a 13-run win in a see-sawing contest at the WACA Ground, rolling their opponents for 356 in the final over.

But man-of-the-man Green admits he thought the run out had come too late after Head destroyed WA’s inexperienced bowling attack, with the Redbacks looking set to comfortably chase down 370 in the entertaining run-fest.

The aggressive left-hander was one of four centurions for the match - two on each team - and looked like he was playing stick cricket towards the end of his stunning 86-ball 142, which included six sixes and 15 fours.

Head combined with young opener Harry Neilsen (110 off 118) for a mammoth 226-run second-wicket stand in 25.1 overs before he was caught short going for a second run.

Green fired in an accurate throw from the fine-leg boundary and gloveman Josh Inglis did the rest in the first of four run outs, with Alex Carey gone for a diamond duck, Tom Cooper (7) the victim of a mix-up and Cam Valente (15) the last man to fall in pursuit of quick final-over runs.

“At the time I didn’t really think it was going to matter, they were in a pretty comfortable position,” Green said.

“But hindsight is pretty good, you could see that it probably changed the game at the time but the guys fielded really well.

“I think we got four run outs in the end, on a flat wicket that’s probably how you’re going to get your wickets.”

Head had plenty of fortune along the way, with a pair of dropped WA catches on 32 and 68 and another totally misjudged on the boundary on 80.

But that luck turned as quickly as the visitors were denied a win twice in three days.

“I felt like we were cruising it in but unfortunately a couple of run outs and a few back-to-back wickets chasing that many was always going to turn up the pressure,” Head said.

“Unfortunately we got ourselves in that position and we weren’t good enough at the end.”

Earlier in the day, Australian cricket prodigy Green (144 off 101) and his skipper Shaun Marsh (113 off 110), born 16 years apart, blasted WA to their biggest total against the Redbacks, 5-369, after getting sent in.

The pair put on 156 for the third wicket, with Marsh making it back-to-back 50-over cup centuries - 463 days after his player-of-the-final heroics last season.

The evergreen 37-year-old became WA’s leading run-scorer in domestic one-day history early in his innings, breaking former coach and teammate Justin Langer’s record of 3374.

Once Marsh departed, Green and Josh Inglis, who looked like he was still in Big Bash mode, lifted the tempo with a quickfire 88-run stand in 42 balls.

“The wicket was really good and Shaun Marsh was awesome to bat with at the start,” Green said.

“He took all the pressure off really and then I could just have some fun at the end.”

Both states played new-look outfits with five debutants between them.

WA had just three players available from last season’s final-winning team - Marsh, Green and opener Cam Bancroft - with nine white-ball stars on Australian Twenty20 duties in New Zealand, Hilton Cartwright injured and Matt Kelly rested.

Left-arm tearaway Liam Guthrie (2-55 off 10) was the pick of the first-gamers from either side, bowling with great pace and mixing his lengths up well.

Former Australian limited-overs international Joel Paris (2-62 off 10) and young allrounder Aaron Hardie (2-57 off 7.2) were also among the wickets.

Claremont-Nedlands run machine Nick Hobson didn’t get much of a chance to bat, but took a great catch in the outfield before a sharp throw affected Cooper’s run out.

In bizarre scenes during the first innings, South Australian debutant Peter Hatzoglou had his first List-A wicket for about five seconds when opener Sam Whiteman (43 off 47) was given out caught behind, only for the umpire to reverse his decision.