Check the biggest (sketchy) streaming sites
If you'd rather not rely on someone's steady hand to get your prizefighting fix, your next best option is checking the most popular (and totally questionable) streaming sites out there. While we're not in the business of sharing direct links to these pages, we ARE in the business of telling you their names: USAGoals, Stopstream, FirstRow, Sportstream, ATDHE, and Chanfeed (just to name a few).
Whichever one you end up using, you should install a pop-up blocker -- and prepare to deal with a feed that may or may not be glitchy, and almost definitely won't be in HD. That's the price you pay for not paying a price in the first place!
Check out Reddit
If the above sites aren't working for you, Reddit's a great resource for finding working streams of live events: hit up the Boxing subreddit, or just type "Pacquiao stream" into the site-wide search bar on the top right of the page. Users upvote posts with working stream links, so the results tend to be more reliable than simply hitting sites at random.