First check to see if there really is an exhaust leak.
(Big rag held over the tailpipe when it's running. Listen for the loud hissing sound to know it leaks)
If there is no exhaust leak, start looking at plugs/Ignition system. As it's an N/A, check the distributor cap etc too. I say this because it happened so quickly, could have been an electrical connection that has gone bad.
As this happens under power with popping noises, this just sounds like a plug breaking down under load. If it was a hole in the exhaust manifold or close to the manifold, the popping noises would happen on the over-run as it sucks in air into the hot exhaust.
I had a set of plugs break down a couple of weeks ago on a track day. Car started popping and farting about under load all over the place.
Just another direction in which to look. HTH.