It depends on how good your ground game is. You need to ask yourself if you're a better striker or wrestler. I'm short (5'8') but stocky (185 lbs) with a lot of upper and lower body strength. I'm not the fastest striker in the world but I hit hard so I'm a ground and pound type. I also know quite a few wrestling (I wrestled in high school) and mixed martial arts submission moves that I can actually execute quite well, which leads me to my point; Your fighting style needs to match your ability to execute. Don't take him to the ground and then have a "Now what?" moment. However, don't plan to stand back and have a boxing match or slug it out with someone who is taller or has a longer reach than you, especially if they are a fast striker. It won't matter if you're stronger if you're getting punched in the face repeatedly and can't land any blows of your own. Also, don't rule out fighting dirty. A fight by its very nature IS dirty, has one objective, and only one objective: Beat your opponent.
He might counter with a knee to the head, if you wanna bring him down try a headlock / hip toss but keep him in headlock through the entire move and land on top of him, that'll knock the wind out of him. Loop your thumb through your belt loop so that you still have him in the headlock, that'll free up your other hand to punch.