Across
Cup — runner holds it during service (9)
Hit — almost hit back (4)
Voices raised in terrible argument, referee initially knocked over by players (8)
Capital idea to start with, after one's broken record (6)
In opposite directions, lacquered metalware taken (6)
Big college that is accommodating unknown number (4-4)
See 19
Jumper in equestrian sport with narrow margin of victory (4,4)
Glassy expression's first seen in very upset suitor (8)
12a
Electrical device — more foolish instrument of punishment (6,6)
Southern frontiersman, big chap (8)
17d
Feed unlimited dill, in herbaceous plant (6)
Car from Providence somewhere in Italy (6)
Hunter, head in plaster bloodied on a rock (8)
Sponge cakes right for composer (4)
Most happening to see border in Italian city that's not closed (9)
Down
King spoiling absurd plan (5)
Sailor finds companion on piece of land (7)
See 23
Gun crime at a higher level getting criticism initially (5-2)
English books inclined to be involved (9)
Red skirts — rip off skirting (7)
Compound of zinc's the cure in the end for German intellect (9)
Variety in a wine list a growing concern for heavy drinkers, perhaps? (9)
Evidence hack, say, was there to find clue — nothing concerning promotion in it (9)
See 22
Greek song others performed around piano (7)
With drunken glee I'm glugging absinthe to begin with — how far gone? (7)
Scanning text quickly, Twitter covering fear of urinals? (5,7)
3d
Ride straight on up the creek (5,5)
Type letters or click words in the clue