I solved this puzzle feeling somewhat under duress last night, in the wee small hours after a convivial evening, and while my run of sub-10-minute times has not been shattered, the relative straightforwardness of the parsings below makes me think that I actually made heavy weather of this one. Quite a lot of the answers did go straight in upon reading the clue, but then I floundered in other places, ending sluggishly at the 9ac/3dn crosser where I couldn't think what to put before ASSES (if not PALLI) at all, and cursed the amount of time I spent learning the names of books of the Bibles when I could have been concentrating harder on maths and the sciences, as the obtuse angle clue became my LOI.
Or perhaps this was harder than I'm giving it credit for: certainly the phrasing of the clues seemed unusual in places, and I wasn't entirely familiar with, e.g. the trespasser, the pony (it's normally a dog, right?), and the office (in a clue that would have gone much more smoothly if my initial gambler's biff of MONTEVIDEO had paid off). Classicsphobes may have found themselves stymied by the run of Latin and Greek words clustered at the start of the Downs, and hopefully none of the people who didn't know HABAKKUK from their elbow earlier this week attempted to enter SOMINIACS, SOMANIACS or even INSOMNIACS at 4dn. Anyway I liked both the artist clues for lending this puzzle some visual colour, but I'll award my Clue of the Day to 6dn, for the bibulousness of its theme and the well-concealed definition in "funny". Many thanks to our setter!
Across
1 Management of image in muddle after firm gets contract (8)
COMPRESS - PR [management of image] in MESS [muddle] after CO [firm]
5 Beastly female given crown? I couldn't care less! (2,4)
SO WHAT - SOW [beastly female] given HAT [crown]
8 A bit of time given to something in TV break? (3)
TAD - T [time] given to AD [something in TV break]
9 Small containers for drink put down beside donkeys (10)
DEMITASSES - DEMIT [put down] beside ASSES [donkeys]
10 Sailor given marks — keeps off the rum? (8)
ABSTAINS - AB [sailor] given STAINS [marks]
11 Moved slowly, being nicked, quietly led off (6)
INCHED - {p}INCHED [nicked, P (= quietly) "led off"]
12 Saint always presented as one with foresight (4)
SEER - S E'ER [saint | always]
14 Soldier is kept in old office, back in S American city (10)
VALPARAISO - PARA IS [solder | is] kept in O LAV [old | office] back
17 Course one gets on to pursue prosperity (10)
SUCCESSION - I [one] gets ON to pursue SUCCESS [prosperity]
20 Some feel Kandinsky is revolutionary artist (4)
KLEE - reverse hidden [some .. revolutionary] in {f}EEL K{andinsky}
23 Man in biological unit attached to English university (6)
EUGENE - GENE [biological unit] attached to E U [English | university]
24 Restrictive legislation was slammed by officer protecting navy (4,4)
CORN LAWS - (WAS*) ["slammed"] by COL [officer] protecting RN [navy]
25 Supplicant saying something twice, about to be dismissed with little hesitation (10)
PETITIONER - {re}PETITION [saying something twice, RE (= about) "to be dismissed"] with ER [little hesitation]
26 Tool in pit getting left abandoned (3)
HOE - HO{l}E [pit, getting L (= left) "abandoned"]
27 Baddie pinning queen by the French bed (6)
CRADLE - CAD [baddie] pinning R [queen], by LE [the French]
28 This person, a more confident ruler? (8)
MEASURER - ME A SURER [this person | a | more confident]
Down
1 Purification of member of medieval sect and little relation (9)
CATHARSIS - CATHAR [member of medieval sect] and SIS [little relation]
2 Swimmers from America in the sea, close to shore (7)
MEDUSAE - USA [America] in MED E [the sea | "close" to {shor}E]
3 A particular angle shows church lacking in brightness (6)
RADIAN - RADIAN{ce} [CE (= church) "lacking" in brightness]
4 Corrupt clergy, one hundred in a mission that's phoney (9)
SIMONIACS - C [one hundred] in (A MISSION*) ["...that's phoney"]
5 Toughness of floral components (7)
STAMINA - double def, STAMINA being a Latinate plural of "stamen"
6 Funny group of women like some wine on shelf (9)
WISECRACK - WI SEC [group of women | like some wine] on RACK [shelf]
7 A number of points arose, oddly neglected in explanations (7)
ANSWERS - A NSWE [a | number of points] + {a}R{o}S{e} "oddly neglected"
13 With socialist going to extremes fuss is made again (9)
RECREATED - with RED [socialist] "going to extremes", CREATE [fuss]
15 Articulate professional, name with a bit of weight (9)
PRONOUNCE - PRO N [professional | name] with OUNCE [bit of weight]
16 Men set about Everest, unfortunately make a wrong move (9)
OVERSTEER - OR [men] set about (EVEREST*) ["unfortunately]
18 Quietly stops one taking excessive interest in trespasser (7)
USURPER - P [quietly] stops USURER [one taking excessive interest]
19 Pony incapacitated initially in inadequate accommodation? (7)
SHELTIE - I{ncapacitated} "initially" in SHELTE{r} ["inadequate" accommodation]
21 Hide in state of agitation with prince finally entering (7)
LEATHER - LATHER [state of agitation] with {princ}E "finally" entering
22 Painter missing the bottom bit of entrance (6)
INGRES - INGRES{S} ["missing the bottom bit of" entrance]
Or perhaps this was harder than I'm giving it credit for: certainly the phrasing of the clues seemed unusual in places, and I wasn't entirely familiar with, e.g. the trespasser, the pony (it's normally a dog, right?), and the office (in a clue that would have gone much more smoothly if my initial gambler's biff of MONTEVIDEO had paid off). Classicsphobes may have found themselves stymied by the run of Latin and Greek words clustered at the start of the Downs, and hopefully none of the people who didn't know HABAKKUK from their elbow earlier this week attempted to enter SOMINIACS, SOMANIACS or even INSOMNIACS at 4dn. Anyway I liked both the artist clues for lending this puzzle some visual colour, but I'll award my Clue of the Day to 6dn, for the bibulousness of its theme and the well-concealed definition in "funny". Many thanks to our setter!
Across
1 Management of image in muddle after firm gets contract (8)
COMPRESS - PR [management of image] in MESS [muddle] after CO [firm]
5 Beastly female given crown? I couldn't care less! (2,4)
SO WHAT - SOW [beastly female] given HAT [crown]
8 A bit of time given to something in TV break? (3)
TAD - T [time] given to AD [something in TV break]
9 Small containers for drink put down beside donkeys (10)
DEMITASSES - DEMIT [put down] beside ASSES [donkeys]
10 Sailor given marks — keeps off the rum? (8)
ABSTAINS - AB [sailor] given STAINS [marks]
11 Moved slowly, being nicked, quietly led off (6)
INCHED - {p}INCHED [nicked, P (= quietly) "led off"]
12 Saint always presented as one with foresight (4)
SEER - S E'ER [saint | always]
14 Soldier is kept in old office, back in S American city (10)
VALPARAISO - PARA IS [solder | is] kept in O LAV [old | office] back
17 Course one gets on to pursue prosperity (10)
SUCCESSION - I [one] gets ON to pursue SUCCESS [prosperity]
20 Some feel Kandinsky is revolutionary artist (4)
KLEE - reverse hidden [some .. revolutionary] in {f}EEL K{andinsky}
23 Man in biological unit attached to English university (6)
EUGENE - GENE [biological unit] attached to E U [English | university]
24 Restrictive legislation was slammed by officer protecting navy (4,4)
CORN LAWS - (WAS*) ["slammed"] by COL [officer] protecting RN [navy]
25 Supplicant saying something twice, about to be dismissed with little hesitation (10)
PETITIONER - {re}PETITION [saying something twice, RE (= about) "to be dismissed"] with ER [little hesitation]
26 Tool in pit getting left abandoned (3)
HOE - HO{l}E [pit, getting L (= left) "abandoned"]
27 Baddie pinning queen by the French bed (6)
CRADLE - CAD [baddie] pinning R [queen], by LE [the French]
28 This person, a more confident ruler? (8)
MEASURER - ME A SURER [this person | a | more confident]
Down
1 Purification of member of medieval sect and little relation (9)
CATHARSIS - CATHAR [member of medieval sect] and SIS [little relation]
2 Swimmers from America in the sea, close to shore (7)
MEDUSAE - USA [America] in MED E [the sea | "close" to {shor}E]
3 A particular angle shows church lacking in brightness (6)
RADIAN - RADIAN{ce} [CE (= church) "lacking" in brightness]
4 Corrupt clergy, one hundred in a mission that's phoney (9)
SIMONIACS - C [one hundred] in (A MISSION*) ["...that's phoney"]
5 Toughness of floral components (7)
STAMINA - double def, STAMINA being a Latinate plural of "stamen"
6 Funny group of women like some wine on shelf (9)
WISECRACK - WI SEC [group of women | like some wine] on RACK [shelf]
7 A number of points arose, oddly neglected in explanations (7)
ANSWERS - A NSWE [a | number of points] + {a}R{o}S{e} "oddly neglected"
13 With socialist going to extremes fuss is made again (9)
RECREATED - with RED [socialist] "going to extremes", CREATE [fuss]
15 Articulate professional, name with a bit of weight (9)
PRONOUNCE - PRO N [professional | name] with OUNCE [bit of weight]
16 Men set about Everest, unfortunately make a wrong move (9)
OVERSTEER - OR [men] set about (EVEREST*) ["unfortunately]
18 Quietly stops one taking excessive interest in trespasser (7)
USURPER - P [quietly] stops USURER [one taking excessive interest]
19 Pony incapacitated initially in inadequate accommodation? (7)
SHELTIE - I{ncapacitated} "initially" in SHELTE{r} ["inadequate" accommodation]
21 Hide in state of agitation with prince finally entering (7)
LEATHER - LATHER [state of agitation] with {princ}E "finally" entering
22 Painter missing the bottom bit of entrance (6)
INGRES - INGRES{S} ["missing the bottom bit of" entrance]