A late change of plans proved a winning move for trainer John McArdle, with El Rocko thriving in wet conditions to claim victory at Moonee Valley on Saturday.

Originally targeting the William Newton VC Handicap (1400m) at Flemington on Anzac Day, McArdle switched gears when he saw a smaller field and rain-affected track conditions for the Ladbrokes Form Genius Handicap (1519m).

“The 1400-metre race yesterday we thought was the race that would be the right one, but I also accepted for this race here,” McArdle said.

“When this race came up with only nine runners, we switched and then when it rained yesterday, we were happy.

“Whenever he gets his toe in the ground, he’s a different horse and he had been running well.”

Providing jockey Jett Stanley with his first victory as a fully-fledged senior rider, El Rocko ($4.20) charged through the wet to beat $4 favourite Chorlton Lane by 2-¾ lengths, with Suparazi ($4.60) a further two lengths behind in third.

McArdle praised Stanley’s execution and how he managed El Rocko during the race.

“Credit to young Jett,” McArdle said.

“He’s a horse that is usually better with something to chase as he is a bit of a thinker, but with the light weight and the conditions today, I said to Jett you might end up outside the leader.

“I said, just don’t let him switch off and to his credit, he rode him perfectly and got the job done.”

Weighing in at a hefty 630 kilograms, El Rocko is a horse that thrives in softer conditions, and McArdle said future plans will revolve around finding suitable wet tracks.

Options include a possible trip to Adelaide for the Group 3 The Cummings Stakes (1600m) at Morphettville on May 10, or a Winter Championships campaign in Melbourne.

“Chasing the rain is the hardest thing and keeping him intact,” McArdle said.

“I think he was up for 17 months last year, and he might be the same again this time.

“He’s 630 kilos. He’s a big lad, so condition wise he’s alright, it’s just keeping him interested and when he gets the wet ground, he certainly switches on.

“It will be interesting to see what they rate him after today, but we’ll chase the rain.

“He is multiple Stakes-placed, and he did run second to Artorius at his first start as a two-year, so he is up to this level, it’s just finding the tracks where it’s wet.”