Sutherland and St George are each one win away from the Sydney Cricket Ground and a shot at some silverware.
Saints and the Sharks secured top four finishes in their Sydney Sixers pool of the Twenty20 Cup with strong victories on Sunday.
Sutherland could return to the SCG in a fortnight as they look to go one better than their T20 Cup final loss to Sydney last season.
At Glenn McGrath Oval, Sutherland required two wins in their double header against UTS North Sydney and Eastern Suburbs to have any chance of qualifying for the semi-finals after a slow start to the competition.
In their opening match against Norths in the morning, a tight bowling performance saw Sutherland restrict the visitors to just 7-118 from their 20 overs.
Former Australia Test captain Steve Smith (1-17) and NSW Sheffield Shield spinner Daniel Fallins (2-16) gave up just 33 runs between them for their eight overs with the ball.
In reply, openers Peter Saroukos (20) and Jarryd Biviano (37) got off to a solid start before Smith made light work of the run chase.
Smith blasted an unbeaten 56 from just 35 balls, including five fours and two sixes, to see Sutherland cruise past the Norths total with four overs to spare.
In their afternoon match, Fallins (4-20) and Sydney Sixers teammate Ben Dwarshuis (3-11) gave their batsmen another good look at victory as they restricted Easts to 9-124 at the close of their innings.
Chris Williams (58 not out) and Smith (33 not out) again eased Sutherland to victory for the loss of one wicket with almost five overs to spare.
The win saw the Sharks squeak past Newcastle for a place in the finals thanks to their superior quotient.
At Allan Border Oval, Mosman could only manage 8-139 batting first as St George captain Nick Stapleton took 3-18.
Saints kept their perfect pool record in tact with a comprehensive eight-wicket win, their fourth from as many matches, as Luke Bartier (56) and Stapleton (33) put on a show in reply.
Sutherland will face Sydney at Drummoyne Oval in their semi-final on Sunday, while St George will welcome Randwick Petersham and former Australia Test opener David Warner to Hurstville Oval.
The winners advance to the preliminary finals to be played at the SCG on December 9.
The T20 Cup final will be played that evening following the completion of the second preliminary final.
Play at Hurstville starts at 2.30pm on Sunday.
