Toyota just caught Nissan with a surprise left hook

Toyota's surprise new venture with Tesla to produce electric vehicles reminds us of the solemn rule of baseball and boxing: It ain't over till it's over.

Nissan has been charging like a bull for two years to get into EVs. CEO Carlos Ghosn absolutely shocked listeners by declaring that he would mass produce electric cars, and Nissan is planning to spend almost $2 billion on a new factory in Tennessee to barrel ahead.

Throughout it all, Toyota has been oddly silent about electrics.

But Thursday night -- just five days before Ghosn is to arrive in Nashville to put a ceremonial shovel in the ground to start factory construction -- Toyota CEO Akio Toyoda stood smiling next to Tesla's rich young co-founder Elon Musk in California saying that Toyota will now enter the race.

This is what makes the car business so thrilling. Just when somebody thinks they've got a corner of the business locked up, competition explodes behind them and it suddenly no longer matters who was first and who came second.