Could Mike Tyson, in his prime, knock out a tiger with an uncontested
punch?  Answer must be definitive.

I find it difficult to imagine how such an answer could be definitive.
This is a speculative matter. A hypothetical tiger and a Mike Tyson of
days gone by can scarcely be put to the test in any meaningful way,
can they? Maybe a computer simulation could be prepared, but at the
very least, I'd think that extremely detailed specifications of the
tiger would be required. Some tigers are so young or so feeble that
even I could knock them out.

A tiger's head would weigh around 100 pounds, so I think it is
unlikely that any human could hit one hard enough to knock it out.

I am going to say a definitive NO.

A tiger can behead a human just by trying to "play" with them.  I
don't think that Tyson would have been any competition.

If Tiger was carrying his 9-iron, my money would be on him.

He could certainly "eat his children" without much controversy.

LMAO...I assumed you have no idea of the size of an adult male Bengal
or Siberian, do you? The definitive answer is "No"
Mikie would look like a pussy cat next to one of these predators.
http://www.blueplanetbiomes.org/bengal_tiger.htm
http://www.tdscats.com/tiger_facts.html

There is some key wording in his question, "an uncontested punch"

If a tiger was shackled and forced to take a massive blow from one of
the most explosive pound for pound punchers in the history of boxing,
I'm not so sure Tyson couldn't knock him out.

It should be noted that many people consider George Foreman (pre-grill
days) to be the overall hardest puncher to ever grace a ring, often
knocking opponents out with glancing blows.  Head trauma is not a
difficult thing to cause, and I think the same holds true for tigers
of all shapes and sizes.  If anyone could knock out a tiger with one
punch, Foreman in his prime would be my bet.