diff --git a/src/Codeception/Command/Run.php b/src/Codeception/Command/Run.php
index 4184f6f2cb..568b0ccda1 100644
--- a/src/Codeception/Command/Run.php
+++ b/src/Codeception/Command/Run.php
@@ -385,10 +385,10 @@ public function execute(InputInterface $input, OutputInterface $output)
         }
 
         if ($test) {
-            $filter = $this->matchFilteredTestName($test);
-            $userOptions['filter'] = $filter;
+            $userOptions['filter'] = $this->matchFilteredTestName($test);
+        } elseif ($suite) {
+            $userOptions['filter'] = $this->matchFilteredTestName($suite);
         }
-
         if (!$this->options['silent'] && $config['settings']['shuffle']) {
             $this->output->writeln(
                 "[Seed] <info>" . $userOptions['seed'] . "</info>"
@@ -470,7 +470,8 @@ protected function matchSingleTest($suite, $config)
                     list($file) = explode(':', $suite, -1);
                 }
                 $realPath = $cwd . DIRECTORY_SEPARATOR . $file;
-                if (file_exists($realPath) || is_dir($realPath)) {
+                if (file_exists($realPath) && strpos($realPath, $realTestDir) === 0) {
+                    //only match test if file is in tests directory
                     return $this->matchTestFromFilename(
                         $cwd . DIRECTORY_SEPARATOR . $suite,
                         $realTestDir
@@ -537,15 +538,38 @@ protected function runSuites($suites, $skippedSuites = [])
 
     protected function matchTestFromFilename($filename, $testsPath)
     {
+        $filter = '';
+        if (strpos($filename, ':') !== false) {
+            if ((PHP_OS === 'Windows' || PHP_OS === 'WINNT') && $filename[1] === ':') {
+                // match C:\...
+                list($drive, $path, $filter) = explode(':', $filename, 3);
+                $filename = $drive . ':' . $path;
+            } else {
+                list($filename, $filter) = explode(':', $filename, 2);
+            }
+
+            if ($filter) {
+                $filter = ':' . $filter;
+            }
+        }
+
         $testsPath = str_replace(['//', '\/', '\\'], '/', $testsPath);
         $filename = str_replace(['//', '\/', '\\'], '/', $filename);
+
+        if (rtrim($filename, '/') === $testsPath) {
+            //codecept run tests
+            return ['', '', $filter];
+        }
         $res = preg_match("~^$testsPath/(.*?)(?>/(.*))?$~", $filename, $matches);
 
         if (!$res) {
             throw new \InvalidArgumentException("Test file can't be matched");
         }
         if (!isset($matches[2])) {
-            $matches[2] = null;
+            $matches[2] = '';
+        }
+        if ($filter) {
+            $matches[2] .= $filter;
         }
 
         return $matches;
diff --git a/tests/cli/RunCest.php b/tests/cli/RunCest.php
index ad99b0ff7d..e4bcc61fb3 100755
--- a/tests/cli/RunCest.php
+++ b/tests/cli/RunCest.php
@@ -24,6 +24,40 @@ public function runOneFileWithColors(\CliGuy $I)
         $I->seeInShellOutput("\033[35;1mFileExistsCept:\033[39;22m Check config exists");
     }
 
+    /**
+     * https://github.com/Codeception/Codeception/issues/6103
+     */
+    public function runSuiteWhenNameMatchesExistingDirectory(\CliGuy $I)
+    {
+        $I->amInPath(codecept_data_dir('dir_matches_suite'));
+        $I->executeCommand('run api');
+        $I->seeInShellOutput('SuccessCest');
+    }
+
+    public function runTestsDoesntFail(\CliGuy $I)
+    {
+        $I->amInPath(codecept_data_dir('dir_matches_suite'));
+        $I->executeCommand('run tests');
+        $I->seeInShellOutput('SuccessCest');
+    }
+
+    public function runTestsWithFilterDoesntFail(\CliGuy $I)
+    {
+        $I->amInPath(codecept_data_dir('dir_matches_suite'));
+        $I->executeCommand('run tests:^success');
+        $I->seeInShellOutput('SuccessCest');
+
+        $I->executeCommand('run tests/:^success');
+        $I->seeInShellOutput('SuccessCest');
+    }
+
+    public function filterTestsWithoutSpecifyingSuite(\CliGuy $I)
+    {
+        $I->amInPath(codecept_data_dir('dir_matches_suite'));
+        $I->executeCommand('run :^success');
+        $I->seeInShellOutput('SuccessCest');
+    }
+
     /**
      * @group reports
      * @group core
diff --git a/tests/data/dir_matches_suite/api/.gitignore b/tests/data/dir_matches_suite/api/.gitignore
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/tests/data/dir_matches_suite/codeception.yml b/tests/data/dir_matches_suite/codeception.yml
new file mode 100644
index 0000000000..685a815595
--- /dev/null
+++ b/tests/data/dir_matches_suite/codeception.yml
@@ -0,0 +1,8 @@
+actor: Tester
+paths:
+    tests: tests
+    log: tests/_output
+    data: tests/_data
+    support: tests/_support
+settings:
+    memory_limit: 1024M
diff --git a/tests/data/dir_matches_suite/tests/_output/.gitignore b/tests/data/dir_matches_suite/tests/_output/.gitignore
new file mode 100644
index 0000000000..c96a04f008
--- /dev/null
+++ b/tests/data/dir_matches_suite/tests/_output/.gitignore
@@ -0,0 +1,2 @@
+*
+!.gitignore
\ No newline at end of file
diff --git a/tests/data/dir_matches_suite/tests/_support/ApiTester.php b/tests/data/dir_matches_suite/tests/_support/ApiTester.php
new file mode 100644
index 0000000000..a33632c6fa
--- /dev/null
+++ b/tests/data/dir_matches_suite/tests/_support/ApiTester.php
@@ -0,0 +1,25 @@
+<?php
+
+
+/**
+ * Inherited Methods
+ * @method void wantToTest($text)
+ * @method void wantTo($text)
+ * @method void execute($callable)
+ * @method void expectTo($prediction)
+ * @method void expect($prediction)
+ * @method void amGoingTo($argumentation)
+ * @method void am($role)
+ * @method void lookForwardTo($achieveValue)
+ * @method void comment($description)
+ *
+ * @SuppressWarnings(PHPMD)
+*/
+class ApiTester extends \Codeception\Actor
+{
+    use _generated\ApiTesterActions;
+
+   /**
+    * Define custom actions here
+    */
+}
diff --git a/tests/data/dir_matches_suite/tests/_support/_generated/.gitignore b/tests/data/dir_matches_suite/tests/_support/_generated/.gitignore
new file mode 100644
index 0000000000..c96a04f008
--- /dev/null
+++ b/tests/data/dir_matches_suite/tests/_support/_generated/.gitignore
@@ -0,0 +1,2 @@
+*
+!.gitignore
\ No newline at end of file
diff --git a/tests/data/dir_matches_suite/tests/api.suite.yml b/tests/data/dir_matches_suite/tests/api.suite.yml
new file mode 100644
index 0000000000..e3c58bd260
--- /dev/null
+++ b/tests/data/dir_matches_suite/tests/api.suite.yml
@@ -0,0 +1,4 @@
+class_name: ApiTester
+modules:
+    enabled:
+        - Asserts
\ No newline at end of file
diff --git a/tests/data/dir_matches_suite/tests/api/SuccessCest.php b/tests/data/dir_matches_suite/tests/api/SuccessCest.php
new file mode 100644
index 0000000000..c42da05b29
--- /dev/null
+++ b/tests/data/dir_matches_suite/tests/api/SuccessCest.php
@@ -0,0 +1,11 @@
+<?php
+
+
+class SuccessCest
+{
+
+    public function successful(ApiTester $I)
+    {
+        $I->assertTrue(true);
+    }
+}