Across:
   1. Orgy of violence which connects different levels, young or old (7)
   5. see 2dn
   9. Stuffing (sob) knocked out of Irish 2 18 across boy (9)
  10,17dn. Croon about famous stadium, and key player in 24 returning as celebrity (5 8)
  11. Untidy motion being exposed (6)
  12. Shameless promotion, around which reform evaded (8)
  14. Star taking cake at first with ridiculous taunt... and he finally yields highlight (10)
  16. Reprieve ... wanting check, showboat's making a comeback! (4)
  18. see 2dn
  19. Got involved with sporting giant, and yielded (10)
  22. Coast through quarter final via team management (8)
  23. Gain return for being conquered by the pinnacle? (6)
  26. Of foreign descent, American man is Eire-man's stopping (5)
  27. Belts beginner in move to gain riches ultimately (9)
  28. Sportsman's energy supply perhaps lean - gas ran out? (7)
  29. Standard promotion with West: naked exhibitions (7)
Down:
   1. Hothead nut organised partial return, building with ring appearance (7)
   2,5ac,18ac. Stir at alarm ... it's a discipline! (5 7 4)
   3. Working at it, dug in for thorough examination (8)
   4. Clear: notable 21 gain (4)
   5. see 24
   6. Series of offences upset corner (not new) by end of round (6)
   7. Came up with something new, done in a TV frenzy (9)
   8. Opening learner up, reaches in, drubbing lairy youngster in a ghastly way (7)
  13. In raging bull, a nerve exposed perhaps? (10)
  15. Venting of emotions as rich sat around (9)
  17. see 10ac
  18. Retraining, learns a host of attacking devices (7)
  20. Can't stand grand final mixing two sets (7)
  21. Big money game: embracing unknown corruption, bingo! (6)
  24,5dn. My old way beaten, overcome by light touch of a master (5 10)
  25. Close to end ... referee to cancel! (4)