A sensational spell of swing bowling gave RSL-Colts the upper-hand late on in day one of the RSL-Pinnington Cup clash with Macquarie.
A number of Colts' batsmen failed to kick on after making starts and as a result they failed to bat out the day, with Macquarie knocking the ladder leaders over for 189.
The Blues then had to bat for just the final seven overs of the day but Malouf's terrorising spell put them right on the back foot.
Malouf finished with a terrific 5/4 from three overs to leave the Blues reeling at 5/18 at stumps.
Malouf, who has played a number of RSL-Whitney Cup matches this season, was on a hat-trick at one point as three Macquarie batsmen fell without scoring.
Earlier in the day, Sam Bass (33), Anthony Atlee (33), Nathan Jones (32), and Josh Smith (30) had all chipped in for a Colts side already all-but certain to finish as minor premiers.
Harry Brennan claimed 3/18 for Macquarie before he finished 3 not out at stumps.
CYMS went into the final round of the season needing a win and results to go their way to be any chance of playing finals.
While Saturday was a far from dominant showing, the Cougars will be confident of going on with the job next week after Matt Ellis, Lochie Endacott, and Campbell Watts put the side in a handy position against second-placed Newtown.
Ellis made 54 at Lady Cutler 2 while Endacott made 47 as CYMS made 180.
The Tigers had seven overs to last before stumps and young gun Watts knocked over Adam Davis (2) and Lachla Reid (0) to put his side in charge.
Newtown will resume at 2/10 next Saturday.
Rugby is the side sitting in the all-important third spot currently and it will fancy its chances of holding on to a place in the finals after performing well against Souths on day one at Lady Cutler 3.
Adam Richards' miserly spell of 3/7 from 15 overs and contributions from Darcy Chewings (2/15), Jayden Blake (2/20), and Troy Tracey (2/23) helped Rugby knock over the Hornets for 122 on Saturday.
Rugby openers Roland O'Connor (11 not out) and Koda Sissian (2 not out) then got through the final overs unscathed and helped their side to 0/25 at stumps.
A win for Rugby next week would likely set up a semi-final clash with Newtown while Colts are near-certain to move straight through to this season's grand final.