Across:
   9. Modern form of football played by South American, as Inca is too rough (11)
  10. Stouter heart exposed (3)
  11,24. They took on 15 22 down in 7 19 4 9 opener... their five on court worry like ten by moving lots (3 4 7)
  12. Almost heresy to disrupt gratitude expressed for famous Mother (7)
  13. Notice real inclusion in 4 down perhaps (5)
  14. On air, decides I've allowed comeback, not having iced (9)
  16. In South American house, small and valuable root, a starchy foodstuff (7)
  18. License to change lack of voice (7)
  20. Latin Thor running in multi-discipline event (9)
  22. Set is awful in places (5)
  24. see 11
  26. Charms of backward Southern romance (no opening for "coloreds") (7)
  27. As mentioned in tongue twister about one such, sells becoming seashells (3)
  28. Briefly incorporated hell with partner (at a loss) (2 9)
Down:
   1. Teases one involved in failed stunt (6)
   2. Reformed hood saws timbers for guitars perhaps (8)
   3. Account briefly incurred financial penalty for attack (6)
   4. Second request: somehow bet the lot in one game (10)
   5. Animation time: present (4)
   6. Strangely invert and reverse 15 break (8)
   7.  Provided for XX crowd with signs? (5'1)
   8. Losing head, gripped arrows the wrong way (put legs around!) (8)
  15,22. Lopez famously sang the finale with less reserve (and serious front) for the team that met 11 24 in 7 19 4 9 opener (3 7 6)
  16. Kitty given salty concoction, which gets things happening (8)
  17. Psyche, perhaps, or maybe testosterone? (8)
  19. Worked on a Latin American perhaps? (8)
  21. Silly, dumb, i.e. soaked (6)
  22. see 15
  23. Resist abuse, for your fellow female (6)
  25. Inevitably, you mimic stock endings, and that's very offputting (4)