1. Without failing, riotous raids take to the sky (10)
FLAWLESSLY
LAWLESS (riotous) raids FLY (take to the sky)
7. Potato destroyed, don’t spill the beans, mother! (4)
MASH
MA (mother) + SH (don’t spill the beans!)
9. Man, say, in solver erasing every other letter (4)
ISLE
I[n] S[o]L[v]E[r] (erasing every other letter)
10. Obvious, it’s said (10)
PRONOUNCED
11. Torpor first up, originally nursed (6)
STUPOR
[fir]ST UP OR[iginally] (nursed)
12. Irritable where intervention of second ref backfired, poor substitute (8)
TRAVESTY
TESTY (irritable) where intervention of (VAR)< (second ref, <backfired)
13. Particular birthday where fit hero has become wobbly, tummy initially held in (8)
FORTIETH
(FIT HERO)* (*has become wobbly), T[ummy] (initially) held in
15. Giant ostensibly gigantic, really enormous for starters (4)
OGRE
O[stensibly] G[igantic] R[eally] E[normous] (for starters)
17. Wheel speeds reversed (4)
SPIN
(NIPS (speeds))< (<reversed)
19. Free rent: seemingly embarrassed about that (8)
RELEASED
LEASE (rent), RED (seemingly embarrassed) about that
22. Push on drink for squash! (8)
SUPPRESS
PRESS (push) on SUP (drink)
23. Primate, VIP and famous, looking back (6)
GIBBON
(NOB (VIP) and BIG (famous))< (<looking back)
25. Boxing division attributed to a fight, not straightforward (10)
ROUNDABOUT
ROUND (boxing division) attributed to A + BOUT (fight)
26. Meat from lower back cut from buffalo, indigestible! (4)
LOIN
[buffa]LO IN[digestible] (cut from)
27. Hairy beast bald, it’s rumoured (4)
BEAR
“bare” = BEAR (bald, “it’s rumoured”)
28. Game endured, giving nothing away (5-5)
POKER-FACED
POKER (game) + FACED (endured)
2. Lose out, but for country (7)
LESOTHO
(LOSE)* (*out) + THO (but, though)
3. Dog lead on wrong, I need assistance! (5)
WHELP
W[rong] (lead on) + HELP (I need assistance!)
4. Old drink for commercial trader (8)
EXPORTER
EX (old) + PORTER (drink)
5. Fractious, able to cut long hair for punishment (5,5,5)
SHORT SHARP SHOCK
SHORT (fractious) + SHARP (able to cut) + SHOCK (long hair)
6. Land has supported you, humble servant (6)
YEOMAN
OMAN (land) has supported YE (you)
7. State where name is not false (9)
MINNESOTA
8. Boxing weight lower than others in the end, feel the heat (7)
SWELTER
WELTER (boxing weight) lower than [other]S (in the end)
14. Penne and roti put in a blender? Michelin-starred restaurant wouldn’t have it! (3,6)
TIN OPENER
(PENNE and ROTI)* (*put in a blender)
16. More petite, the girls dancing about (8)
SLIGHTER
(THE GIRLS)* (*dancing about)
18. Invited guest turning company of two into a crowd? (4-3)
PLUS-ONE
Double (cryptic) definition
Two plus one is three. Three’s a crowd
20. Moving this person up, one involved in rigging of vote (7)
EMOTIVE
(ME)< (this person, <up) + I (one) involved in (VOTE)* (*rigging of)
21. Prime Minister nailed up, quit! (6)
DECAMP
(PM (Prime Minister) + ACED (nailed))< (<up)
24. Tree, a piece of cake to climb (5)
BALSA
(A + SLAB (piece of cake))< (<to climb)
I enjoyed this. I hadn’t heard the expression PLUS-ONE, and wasn’t entirely convinced by faced/endured. No real favourites.