diff --git a/mysql-test/main/join_nested.result b/mysql-test/main/join_nested.result
index 5ab94a6b568..1efb2e64116 100644
--- a/mysql-test/main/join_nested.result
+++ b/mysql-test/main/join_nested.result
@@ -1999,3 +1999,55 @@ Note	1003	select `test`.`t3`.`pk` AS `pk`,`test`.`t3`.`c1` AS `c1`,`test`.`t3`.`
 DROP TABLE t1,t2,t3;
 set join_cache_level= @save_join_cache_level;
 set optimizer_switch=@save_optimizer_switch;
+#
+# MDEV-27624: Nested left joins with not_exists optimization
+#             for most inner left join
+#
+set @save_join_cache_level= @@join_cache_level;
+CREATE TABLE t1 (a INT NOT NULL, b INT, c INT);
+INSERT INTO t1 VALUES (1,1,1), (1,2,1), (1,3,1);
+CREATE TABLE t2(a INT NOT NULL);
+INSERT INTO t2 VALUES (1), (2);
+CREATE TABLE t3(a INT not null, b INT);
+INSERT INTO t3 VALUES (1, 1), (2, 1), (3, 1);
+set join_cache_level = 0;
+EXPLAIN SELECT *
+FROM t1
+LEFT JOIN
+( t2 LEFT JOIN t3 ON t2.a = t3.b )
+ON t2.a = 1 AND (t3.b = t1.a AND t3.a > t1.b OR t3.a is NULL)
+WHERE t1.c = 1 AND t3.a is NULL;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
+1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	3	Using where; Not exists
+SELECT *
+FROM t1
+LEFT JOIN
+( t2 LEFT JOIN t3 ON t2.a = t3.b )
+ON t2.a = 1 AND (t3.b = t1.a AND t3.a > t1.b OR t3.a is NULL)
+WHERE t1.c = 1 AND t3.a is NULL;
+a	b	c	a	a	b
+1	3	1	NULL	NULL	NULL
+set join_cache_level = 2;
+EXPLAIN SELECT *
+FROM t1
+LEFT JOIN
+( t2 LEFT JOIN t3 ON t2.a = t3.b )
+ON t2.a = 1 AND (t3.b = t1.a AND t3.a > t1.b OR t3.a is NULL)
+WHERE t1.c = 1 AND t3.a is NULL;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
+1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	3	Using where; Not exists; Using join buffer (incremental, BNL join)
+SELECT *
+FROM t1
+LEFT JOIN
+( t2 LEFT JOIN t3 ON t2.a = t3.b )
+ON t2.a = 1 AND (t3.b = t1.a AND t3.a > t1.b OR t3.a is NULL)
+WHERE t1.c = 1 AND t3.a is NULL;
+a	b	c	a	a	b
+1	3	1	NULL	NULL	NULL
+DROP TABLE t1, t2, t3;
+set join_cache_level= @save_join_cache_level;
+# end of 10.3 tests
diff --git a/mysql-test/main/join_nested.test b/mysql-test/main/join_nested.test
index eaf754fb0ca..6b2ae9a457f 100644
--- a/mysql-test/main/join_nested.test
+++ b/mysql-test/main/join_nested.test
@@ -1419,3 +1419,41 @@ DROP TABLE t1,t2,t3;
 set join_cache_level= @save_join_cache_level;
 
 set optimizer_switch=@save_optimizer_switch;
+
+--echo #
+--echo # MDEV-27624: Nested left joins with not_exists optimization
+--echo #             for most inner left join
+--echo #
+
+set @save_join_cache_level= @@join_cache_level;
+
+CREATE TABLE t1 (a INT NOT NULL, b INT, c INT);
+INSERT INTO t1 VALUES (1,1,1), (1,2,1), (1,3,1);
+
+CREATE TABLE t2(a INT NOT NULL);
+INSERT INTO t2 VALUES (1), (2);
+
+CREATE TABLE t3(a INT not null, b INT);
+INSERT INTO t3 VALUES (1, 1), (2, 1), (3, 1);
+
+let $q=
+SELECT *
+FROM t1
+     LEFT JOIN
+     ( t2 LEFT JOIN t3 ON t2.a = t3.b )
+     ON t2.a = 1 AND (t3.b = t1.a AND t3.a > t1.b OR t3.a is NULL)
+WHERE t1.c = 1 AND t3.a is NULL;
+
+set join_cache_level = 0;
+eval EXPLAIN $q;
+eval $q;
+
+set join_cache_level = 2;
+eval EXPLAIN $q;
+eval $q;
+
+DROP TABLE t1, t2, t3;
+
+set join_cache_level= @save_join_cache_level;
+
+--echo # end of 10.3 tests
diff --git a/mysql-test/main/join_nested_jcl6.result b/mysql-test/main/join_nested_jcl6.result
index 541cd47bf04..338705c0a29 100644
--- a/mysql-test/main/join_nested_jcl6.result
+++ b/mysql-test/main/join_nested_jcl6.result
@@ -2008,6 +2008,58 @@ Note	1003	select `test`.`t3`.`pk` AS `pk`,`test`.`t3`.`c1` AS `c1`,`test`.`t3`.`
 DROP TABLE t1,t2,t3;
 set join_cache_level= @save_join_cache_level;
 set optimizer_switch=@save_optimizer_switch;
+#
+# MDEV-27624: Nested left joins with not_exists optimization
+#             for most inner left join
+#
+set @save_join_cache_level= @@join_cache_level;
+CREATE TABLE t1 (a INT NOT NULL, b INT, c INT);
+INSERT INTO t1 VALUES (1,1,1), (1,2,1), (1,3,1);
+CREATE TABLE t2(a INT NOT NULL);
+INSERT INTO t2 VALUES (1), (2);
+CREATE TABLE t3(a INT not null, b INT);
+INSERT INTO t3 VALUES (1, 1), (2, 1), (3, 1);
+set join_cache_level = 0;
+EXPLAIN SELECT *
+FROM t1
+LEFT JOIN
+( t2 LEFT JOIN t3 ON t2.a = t3.b )
+ON t2.a = 1 AND (t3.b = t1.a AND t3.a > t1.b OR t3.a is NULL)
+WHERE t1.c = 1 AND t3.a is NULL;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
+1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	3	Using where; Not exists
+SELECT *
+FROM t1
+LEFT JOIN
+( t2 LEFT JOIN t3 ON t2.a = t3.b )
+ON t2.a = 1 AND (t3.b = t1.a AND t3.a > t1.b OR t3.a is NULL)
+WHERE t1.c = 1 AND t3.a is NULL;
+a	b	c	a	a	b
+1	3	1	NULL	NULL	NULL
+set join_cache_level = 2;
+EXPLAIN SELECT *
+FROM t1
+LEFT JOIN
+( t2 LEFT JOIN t3 ON t2.a = t3.b )
+ON t2.a = 1 AND (t3.b = t1.a AND t3.a > t1.b OR t3.a is NULL)
+WHERE t1.c = 1 AND t3.a is NULL;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	Using where
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	2	Using where; Using join buffer (flat, BNL join)
+1	SIMPLE	t3	ALL	NULL	NULL	NULL	NULL	3	Using where; Not exists; Using join buffer (incremental, BNL join)
+SELECT *
+FROM t1
+LEFT JOIN
+( t2 LEFT JOIN t3 ON t2.a = t3.b )
+ON t2.a = 1 AND (t3.b = t1.a AND t3.a > t1.b OR t3.a is NULL)
+WHERE t1.c = 1 AND t3.a is NULL;
+a	b	c	a	a	b
+1	3	1	NULL	NULL	NULL
+DROP TABLE t1, t2, t3;
+set join_cache_level= @save_join_cache_level;
+# end of 10.3 tests
 CREATE TABLE t5 (a int, b int, c int, PRIMARY KEY(a), KEY b_i (b));
 CREATE TABLE t6 (a int, b int, c int, PRIMARY KEY(a), KEY b_i (b));
 CREATE TABLE t7 (a int, b int, c int, PRIMARY KEY(a), KEY b_i (b));
diff --git a/sql/sql_join_cache.cc b/sql/sql_join_cache.cc
index 86df1d32bd9..0804f4f9463 100644
--- a/sql/sql_join_cache.cc
+++ b/sql/sql_join_cache.cc
@@ -2287,11 +2287,7 @@ enum_nested_loop_state JOIN_CACHE::join_matching_records(bool skip_last)
   int error;
   enum_nested_loop_state rc= NESTED_LOOP_OK;
   join_tab->table->null_row= 0;
-  bool check_only_first_match=
-    join_tab->check_only_first_match() &&
-    (!join_tab->first_inner ||                            // semi-join case
-     join_tab->first_inner == join_tab->first_unmatched); // outer join case
-  bool outer_join_first_inner= join_tab->is_first_inner_for_outer_join();
+  bool check_only_first_match= join_tab->check_only_first_match();
   DBUG_ENTER("JOIN_CACHE::join_matching_records");
 
   /* Return at once if there are no records in the join buffer */
@@ -2355,7 +2351,34 @@ enum_nested_loop_state JOIN_CACHE::join_matching_records(bool skip_last)
         Also those records that must be null complemented are not considered
         as candidates for matches.
       */
-      if ((!check_only_first_match && !outer_join_first_inner) ||
+
+      bool not_exists_opt_is_applicable= true;
+      if (check_only_first_match && join_tab->first_inner)
+      {
+        /*
+          This is the case with not_exists optimization for nested outer join
+          when join_tab is the last inner table for one or more embedding outer
+          joins. To safely use 'not_exists' optimization in this case we have
+          to check that the match flags for all these embedding outer joins are
+          in the 'on' state.
+          (See also a similar check in evaluate_join_record() for the case when
+           join buffer are not used.)
+        */
+	for (JOIN_TAB *tab= join_tab->first_inner;
+             tab && tab->first_inner && tab->last_inner == join_tab;
+             tab= tab->first_inner->first_upper)
+	{
+          if (get_match_flag_by_pos_from_join_buffer(rec_ptr, tab) !=
+              MATCH_FOUND)
+	  {
+            not_exists_opt_is_applicable= false;
+            break;
+          }
+        }
+      }
+
+      if (!check_only_first_match ||
+	  (join_tab->first_inner && !not_exists_opt_is_applicable) ||
           !skip_next_candidate_for_match(rec_ptr))
       {
 	read_next_candidate_for_match(rec_ptr);