Three answers per commenter as usual till 6 PM (Annotations compulsory)
Please provide all your answers in one comment.
This crossword was set by Ramki Krishnan.
Thanks to Kumaresh Ramakrishnan of IIT(M) for sharing this with us.
ACROSS
1 Butcher starting to marinate fish (6)
5 No. 1 in cryptics? He's a member playing ingeniously - our new winner (8)
9 FDA ruled compound to be terrible (8)
10 Opposing extremely crass jokes (6)
11 School pins notice for review (10)
12 Want to massage, say (4)
13 His work could be highly noted (8)
16 In April, days are long, ultimately sultry, scorching sun on top (6)
17 Tricks and passes out, reportedly (6)
19 Unusual mess I clear up (8)
21 Soldier's pledge (4)
22 Showing devotion when welcoming cleric at one time (10)
25 Shape of coarse rug I finally rejected (6)
26 Avoiding exercise (8)
27 A French composer's works out (8)
28 Most painful...therefore, take a break (6)
DOWN
2 Expert wearing an overall (5)
3 Understanding Agra's princely homes (5)
4 Results of massaging feet and face regularly with sulphur (7)
5 Dog runs to a worker of mine (7)
6 Con a good saint to become corrupt (7)
7 Possible workaround, with cunning, talent, and a bit of intelligence (9)
8 Together, they play or box, running around, primarily (9)
14 Frank not quite helping in surgery (9)
15 At first Professor Linnaeus moved to India perhaps (9)
18 Drink's on me? Excellent! (7)
19 Irons Penny's clothes, except the top (7)
20 Annoys, mostly in contests (7)
23 Winning a top (5)
24 They could be used for navigating a golf course (5)
Enjoy.