Will it supply power: YES
Will it work long term: doubtfull.
If your PSU does not have a 6pin connector then it was never designed for gaming.
Best case scenario it is an OEM (Dell, HP, Acer, etc) power supply which will be pushed to its limits.
Worst case scenario it is a cheapo power supply that has no safegaurds and when it dies (not if but when) it will fry the rest of your parts with it!