This matchup will be more interesting, I believe, than the main event. Mo Lawal is a converted wrestler looking to parlay his cockiness into gold; Mousasi is an ever-improving force who has trained with the best and prides himself on being a consummate warrior. Lawal has never faced a well-rounded fighter at the top of the game - so this will be a real coming out party for Mo "King" Lawal.
The best tactics for Lawal will be to rediscover wrestling and make this a ground and pound affair. I predict that when Lawal gets Mousasi to the ground - he will find the arm bar and knee bar attempts very troubling. That will make him pause. Mousasi has been pressed by larger and faster grapplers like Sokoudjou so Mousasi will not be phased by it. On the feet, look for Mousasi to stick and move before giving "King" Mo Lawal a taste of top flight competition.
This may be a long drawn out contest, but I predict it will go Mousasi's way.