Beat high-authority websites, but with weak on-page optimization?

Can I beat a high authority website which has weak on-page optimization? How hard would it be?

bump1

yes yu can.

Anything is possible, what you have to ask yourself is will it be worth it? If you will be making a lot of money then sure go for it and once you succeed every hour of work will be paid back! Take it slow and think long term.

If you are an SEO noob, then i would recommend you to start with low competition terms to get your feet wet and also to see results faster. Results will encourage you to continue with your hard work..

why not?! On-page SEO doesn't matter much for google these days. Sites are ranking because of the links mostly not because of the on-page optimization. The question is not how well optimized a site is on-page but how relevant it is, how big, how many links it has and what kind of links. Obviously in your case probably has lots of good links since you say it is an authority site. However a site like wikipedia has very few pages about a specific topic. If this is the case then it is doable. If however that site is about that keyword, i mean all the site is centered around that topic/keyword then it will be very difficult.