MariaDB 10.2

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create table game 
( id int primary key,
  matchid int,
  ordinal int
);
insert into game
  (id, matchid, ordinal)
values
  (1, 1, 1),
  (2, 1, 1),
  (3, 1, 1),
  (4, 1, 1),
  (5, 1, 2),
  (6, 1, 2),
  (7, 1, 2),
  (8, 2, 1),
  (9, 2, 2),
  (10, 3, 3)
  ;
  
DELETE g.*
FROM game AS g
  JOIN 
   ( SELECT matchid, ordinal, min(id) AS id 
     FROM game
     GROUP BY matchid, ordinal
     -- HAVING count(*) > 1
   ) AS d
   ON  g.matchid = d.matchid
   AND g.ordinal = d.ordinal
   AND g.id > d.id ;
select * from game ;


id
matchid
ordinal


1
1
1

5
1
2

8
2
1

9
2
2

10
3
3