Penrith cricket first grade could claim outright victory when play resumes against Randwick-Petersham at Coogee Oval on Saturday.
Josh Lalor snared six wickets as the hosts crumbled to be bowled out for 59.
Penrith declared at 4-240 in 59 overs.
Luke Morrissey smashed 105 not out while Brent Williams's 72 was a handy contribution.
Randwick Petersham are 0-6 in their second innings.
Blacktown is also in a good position against Northern Districts at Joe McAleer Oval.
Northern Districts are 4-40 in reply to Blacktown's total of 194.
Sports club workshop
Sports club volunteers and committee members can attend a free workshop covering business and strategic planning.
Penrith City Council is helping subsidise the workshop which the NSW Office of Communities Sport and Recreation will deliver on Wednesday, November 21.
Penrith mayor Mark Davies said: "Planning makes sense and this workshop will point out the advantages, how to plan step by step including doing an analysis of your club's strengths, weaknesses, opportunities and threats.
"This workshop will help you tap into the wealth of knowledge already out there. Learn the short cuts, save time and energy."
To book, call Sport and Recreation on 13 13 02 or email Miguel.firstname.lastname@example.org.