First time posting but I have been reading the forum for the last year.
I have a 34 lb well exercised boy named Zeke that loves the dog park so much I can't imagine ever taking that away from him. The current routine is a 2-3 mile walk in the morning and then 1.5 mile walk to the dog park (stay ~45 min) then walk home. Non dog park days we do a 4-6 mile hike.
I nick named him the instigator. He is always looking to play with German Shepards, Huskys and Pit bulls.
I have found that sometimes when Zeke is too rested he can get a little too rough. Never biting or growling at another dog but if the other dog doesn't seem interested and he persists I give Zeke the hook and we head home. I suggest you exercise him before going next time and see how he does.
I can't control the other dogs but I'm vigilant at all time when I'm there. Looking for signs that things might be escalating and I just leave if they are. Sometimes I'm only there for a few minutes but that's ok. It's worth it to me if you could see the look he gives me everyday about 5 pm. I swear he knows how to read a clock.
The other thing is not all dog parks are the same. We have been to at least 30 in the past year (We have a RV) and some are much better than others as far as attentive owners.