Quick Finish

Then Build 1 zealot when it comes out and another gateway
When your zealot comes out, search every base on the map with him and when you find him get out and wait outside his base so you can see when he is going to attack.
Build 3 or 4 more gateways with zealots coming also.
(you should always be buiding pylons and probes while doing this)
Get gas from an assimulator, build cybernetics core
After a while start building dragoons and get your one zealot in front of his base if not dead already and see what he has.
unless he is a newbie then your zealot will die.
if he is really good Tech up with goons zealots.
build a citadel of adun and robotics facility. After, you get the get a templar archive and observatory.
Keep pumping out goons and zealots and when you have enough gas get some dark templars. observers are very cheap so build those.
If you were truly teching up you should have maxed out by now having 200/200 with some cannons scattered around your base.
AFter check again with wat he has and attack...

Good Luck.

Some people have different time spans to be able to pull off this trick.

Newbies:30-40 mins.
Mediates:20-30 mins.
Experts: 10-20 mins.
Me and my friend: 9 mins.