pull off one of the biggest upsets of the Argus Open so far.

The duo took on third seeds, Mark Cordeiro and Eldon Daniels in the quarter-finals of the tournament and saw them off 4-6, 6-3, 6-2 at Tennis Stadium.

The favourites took the first set, but they allowed their opponents to force two breaks of serve in the next and lost it 6-3.

Leader's cunning cross court volleys and timely drop shots forced both Daniels and Cordeiro into errors at the net -- and this paved the way for the underdogs to shine.

When Daniels was broken in the decider there was no looking back and Leader and Kennedy roared into a 4-1 lead from which their opponents were unable to recover.

The victory earned the pairing a date with top seeds James Collieson and Michael Way in the semi-finals -- the favourites going through on default after Darian Thomas and Kenneth Pearman got the match time mixed up.

In the mixed doubles, the veteran line-up of Julie Lunn and Eric Collins needed all their experience to see off Ashley Brooks and Kris Frick 7-5, 2-6, 6-4.

Collins said: "We were indeed fortunate to win. A little more experience and both of our opponents are going to be hard to beat.'' Eldon Daniels, second seed in the mens A singles, beat Wilfred Gonsalves 6-4, 7-6, (7-3) and will face either Jovan Whitter or Chris Harris in the quarter-finals.

Pat Pamplin, meanwhile, defeated teenager Chris Lambert 7-5, 6-3 and Eugene Woods and Natalie Nisbitt beat Mike Levon and Sandra Wells 3-6, 7-5, 4-1 (ret).