I don't think it would have changed the outcome
How many rings would Montana have if his SB opponents had two first quarters and he didn't have a 4th?
The match was following the same pattern as their other matches. Novak's physicality started to rise, Nadal's was at the point where his physical spurts had to be selective. That's exactly the formula that gets them to probably a tie breaker in the 4th that Novak would have won, then the tennis world would have gotten a real 4th quarter.
Watch the replay and listen to Johnnie Mac, who might be the most insightful commentator in American sports. Listen to his verbal body language, he could sense that this was going to a 5th set. Then came the break.
That crazed Serb is pissed. Wait till he pushes Nadal all over the court at Wimbeldon.