Mis-matches in weight. How long do you think one of the best jr flyweights in the world would last

On the topic of mis-matches and the length of fights, back in the day, there were proposition fights where is a bigger guy fought a much smaller guy, monetary awards for either fighter were given for the stoppage or lasting the distance.

Example: Jack Johnson vs. Young Peter Jackson. Johnson was 6'1" tall, about 190 pounds. Young Peter Jackson was about 5'6" tall, and a welterweight. Say 147 pounds. Johnson had roughly a 43-pound advantage here, and would have received more money if he stopped Jackson. He failed to do so, Young Peter lasted the distance of 12 rounds. Score one for the smaller man, he proved a lot

Since Jr Flyweights have been a hot topic here of late, how long do you think one of the best jr flyweights in the world would last vs. say one of the best ring magazine heavyweight champions from 1990 to current?

Rules: If the jr fly last 3 rounds and goes down less than three times he wins the bonus money, which is $100k. This prevents falling down and getting back up at the the count of 8-9, and repeating the process to last rounds. If the Heavyweight champion stops him in less than 3 rounds, he wins the bonus money of $100k. Both fighters are paid 50k regardless of the outcome for the short nights work. If there is a DQ, that fighter does not get paid at all! My hunch is most will say its over quickly, but I'm not 100% sure.

 

Edit on the rules: DQ is a loss and you don't get paid at all! In theroy it should end on the first clean punch to the head or body. Or start the beginning of the end in a matter of seconds.. But with two counts to buy 18-19 seconds, and a neutral corner rule, I think the best jr fly ever could clear the minute mark vs. one of the best ring magazine heavyweight champions, post 1990. That is if he didn't lose his nerve, or quit after being hit hard once which could very well happen.