Really? Most of the sources I have read have said that the Gripen is outclassed in pretty much every category except cost with the Eurofighter.
I can certainly agree that the Eurofighter project has been ruinously expensive and undercapable for the cost, but for all that, it is still a better plane than the Gripen.
As I alluded to, a Gripen might get lucky in the hands of a skilled pilot, just as the Gloster Gladiator won air battles on occasion over ostensibly more advanced German aircraft, but all other things being equal, the Eurofighter is going to win.
And the Gloster Gladiator is biplane totally different category. That comparison isn't even a valid one. Gripen and Eurofighter are both 4+ generation fighters. Both are canard and delta winged, low observable modern fighters but neither of them are stealth. Both have very good aerial kinematics, AESA radar, advanced avionics, senors, long range BVR weapon suite and standoff range weapon. Both will be seeing each other about the same time. As to who will win an aerial engagement will depend on the overall dynamics of the situation. But to say all things being equal Eurofighter will always win is just silly fan boy enthusiasm. Eurofighter really has nothing that gives it an overwhelming tactical edge against the Gripen.
Besides one-to-one marginal difference matters very little into overall strategic calculation. The ability to pack more punch with fewer dollars is a much more important consideration. And that is where the Gripen punches holes inside the overpriced and under-performing Eurofighter.