Alternative to window function in MariaDB 10.1 - syntax

Question

I have a windows function (over, partitioned by) in my code:
FROM (SELECT wp_posts.id,
wp_postmeta.post_id,
post_title,
post_type,
meta_value,
Row_number()
OVER(
partition BY post_title
ORDER BY wp_postmeta.meta_value) rn
but apparently this isn't supported on MariaDB before 10.2 (-I am using 10.1). Could someone please suggest alternative code which is both efficient and works on MariaDB 10.1 also?
dbfiddle provided, unfortunately with only MariaDB 10.2 as the oldest; can't test 10.1 directly here
create table wp_posts (
ID integer primary key auto_increment,
post_title varchar(30),
post_type varchar(30)
);
✓
create table wp_postmeta (
ID integer primary key auto_increment,
post_id integer,
meta_key varchar(30) not null default '_regular_price',
meta_value integer not null
);
✓
insert into wp_posts (post_title, post_type) values
('Apple Pie','Product'),
('French Toast','Product'),
('Shepards Pie','Product'),
('Jam Pie','Product'),
('Jam Pie','Product'),
('Plate','Not a Product'),
('Bucket','Not a Product'),
('Chequebook','Not a Product'),
('French Toast','Product'),
('French Toast','Product'),
('Banana','Product'),
('Banana','Product'),
('Banana','Product');
✓
insert into wp_postmeta (post_id, meta_value) values
(1,10),
(2,5),
(3,9),
(4,8),
(5,11),
(6,12),
(7,10),
(8,6),
(9,1),
(10,1),
(11,7),
(12,2),
(13,2);
✓
-- Deleting all duplicate products in wp_posts table
DELETE FROM wp_posts
WHERE id IN (SELECT id
FROM (SELECT id,
post_title,
post_type,
meta_value
FROM (SELECT wp_posts.id,
wp_postmeta.post_id,
post_title,
post_type,
meta_value,
Row_number()
OVER(
partition BY post_title
ORDER BY wp_postmeta.meta_value) rn
FROM wp_postmeta
JOIN wp_posts
ON wp_postmeta.post_id = wp_posts.id
WHERE wp_posts.post_type = 'Product'
AND wp_postmeta.meta_key = '_regular_price'
) t
WHERE t.rn <> 1) AS aliasx);
✓
db<>fiddle here