THEME:   final -ANCE in two-word phrases changed to ANTS, a homonym that changes the meaning of the original phrase   
GOOD ONES:   "Block that kick" and "Dee-fense!"?   SPORTINGCHANTS [sporting chance]    
Temporarily contribute helpers?   LENDASSISTANTS [assistance]   
Kind of a drag?   MAIN [as in "main drag": sadly I'm reminded of the horrid rock song of that name]   
Head lock   TRESS [oldie but goodie]   
Welcoming sight?   MAT [wonder if "site" would have worked]      
BTW:   It took me awhile to see that the -ANTS endings were homonyms for -ANCE.  I suspect it might easily have been missed.             
Supper preceder   GRACE [note that "dinner preceder" might not work so well since 
dinner tends to be more formal, more sophisticated; and, somehow, less likely to be preceded by grace.  Dan has a good ear.]      
I think the cluing throughout was above par --- not necessarily punny or humorous, just clever.      
RATING: 
 
  
   Three grins = Loved it; Two grins = Enjoyed it; One grin = A bit bland for my taste; One teardrop = Not much fun