What happened?

So yesterday my friend and I decided to pull off just for kicks. My 2007 toyota tacoma prerunner with a locker vs a 1998 jeep grand cherokee 4wd. Well round one was both in 2wd and open diff. I broke traction right off the bat. second round was locked diff vs. 2wd jeep. He still manage to win. Last but not least locked diff vs 4lo. I won? How does this make sense? And why was I loosing traction everytime when he was in 2wd and I was locked? This was on asphalt so I didnt really give the taco hell because I got to keep my tires up intill August. But were pulling off on a clay road next weekend and I need some tips to pull that S.O.B clear across!

 

Yeah, he had street radials and I have rugged trails. As weight I think my bed weighs alot less then the back of his suv