In better news during the week, Mariners youngster Jordan Clark claimed a five-wicket haul, including a hat-trick, for Australia against Pakistan in the Under 16s international in Dubai.
Clark is away, with Rockingham-Mandurah teammate Damien Burrage, who took 3/31 in the first Twenty20 game, as the pair come under the notice of the National Talent Pathway.
First grade batted first at Fletcher Park but quickly struck trouble.
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READ NOWMitch Green stood firm in his knock of 36 and Dane Ugle struck 30 but there was little else to write home about in the innings of 121.
Perth easily wiped off the runs, with just one wicket down and half the overs to play with. Kyle Gardiner took an early wicket to finish with 1-40.
It was much the same story for second grade at Lark Hill with the Mariners bundled out for 67.
The Demons comfortably made their way to victory at 1-68 in the 18th over.
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Third grade went down by 70 runs at Fletcher Park after Perth amassed 9-220 from their 45 overs.
Captain Nick Willis grabbed the best figures with 3-42, while Aidan Andrews made life difficult for the Demons with 2-27 from his nine overs.
Willis also top scored with 27 and Chris Phelps chipped in with 24 but Rockingham-Mandurah fell short for 150.
A last over thriller fell Perth’s way at Lark Hill in the fourth grade encounter by two wickets.
The Mariners batted first, scoring 189 when dismissed after 42 overs.
Sean Guppy gave the innings impetus, scoring 65 and got support from Nathan Anderson (49).
Anderson wheeled away to take 2-38 in the Demons’ response but the visitors found enough in the nick of time.
The Under 17s were outplayed to the tune of 98 runs after making 120 in the 30 over match.
Kai Harrison continued his consistent season with the ball, taking season best figures of 4-34 in Perth’s 4-218.
The Mariners slipped to a 21-run loss in the Under 15s after cobbling together 8-115.
The Demons got home with three wickets lost, finishing at 5-136.
Rockingham-Mandurah were outplayed by the Demons in Round 11 and will need to find confidence before the two day match against Bayswater-Morley, starting this Saturday.