diff --git a/src/wp-includes/block-template.php b/src/wp-includes/block-template.php
index 945b96b027..b267c4ea8f 100644
--- a/src/wp-includes/block-template.php
+++ b/src/wp-includes/block-template.php
@@ -45,7 +45,7 @@ function locate_block_template( $template, $type, array $templates ) {
 		$templates = array_slice( $templates, 0, $index + 1 );
 	}
 
-	$block_template = resolve_block_template( $type, $templates );
+	$block_template = resolve_block_template( $type, $templates, $template );
 
 	if ( $block_template ) {
 		if ( empty( $block_template->content ) && is_user_logged_in() ) {
@@ -92,12 +92,14 @@ function locate_block_template( $template, $type, array $templates ) {
  *
  * @access private
  * @since 5.8.0
+ * @since 5.9.0 Added the `$fallback_template` parameter.
  *
  * @param string   $template_type      The current template type.
  * @param string[] $template_hierarchy The current template hierarchy, ordered by priority.
+ * @param string   $fallback_template  A PHP fallback template to use if no matching block template is found.
  * @return WP_Block_Template|null template A template object, or null if none could be found.
  */
-function resolve_block_template( $template_type, $template_hierarchy ) {
+function resolve_block_template( $template_type, $template_hierarchy, $fallback_template ) {
 	if ( ! $template_type ) {
 		return null;
 	}
@@ -129,6 +131,43 @@ function resolve_block_template( $template_type, $template_hierarchy ) {
 		}
 	);
 
+	$theme_base_path        = get_stylesheet_directory() . DIRECTORY_SEPARATOR;
+	$parent_theme_base_path = get_template_directory() . DIRECTORY_SEPARATOR;
+
+	// Is the current theme a child theme, and is the PHP fallback template part of it?
+	if (
+		strpos( $fallback_template, $theme_base_path ) === 0 &&
+		strpos( $fallback_template, $parent_theme_base_path ) === false
+	) {
+		$fallback_template_slug = substr(
+			$fallback_template,
+			// Starting position of slug.
+			strpos( $fallback_template, $theme_base_path ) + strlen( $theme_base_path ),
+			// Remove '.php' suffix.
+			-4
+		);
+
+		// Is our candidate block template's slug identical to our PHP fallback template's?
+		if (
+			count( $templates ) &&
+			$fallback_template_slug === $templates[0]->slug &&
+			'theme' === $templates[0]->source
+		) {
+			// Unfortunately, we cannot trust $templates[0]->theme, since it will always
+			// be set to the current theme's slug by _build_block_template_result_from_file(),
+			// even if the block template is really coming from the current theme's parent.
+			// (The reason for this is that we want it to be associated with the current theme
+			// -- not its parent -- once we edit it and store it to the DB as a wp_template CPT.)
+			// Instead, we use _get_block_template_file() to locate the block template file.
+			$template_file = _get_block_template_file( 'wp_template', $fallback_template_slug );
+			if ( $template_file && get_template() === $template_file['theme'] ) {
+				// The block template is part of the parent theme, so we
+				// have to give precedence to the child theme's PHP template.
+				array_shift( $templates );
+			}
+		}
+	}
+
 	return count( $templates ) ? $templates[0] : null;
 }
 
diff --git a/tests/phpunit/tests/block-template.php b/tests/phpunit/tests/block-template.php
index 94cea83896..95dab825b9 100644
--- a/tests/phpunit/tests/block-template.php
+++ b/tests/phpunit/tests/block-template.php
@@ -89,16 +89,10 @@ class Tests_Block_Template extends WP_UnitTestCase {
 	 * otherwise equal specificity.
 	 *
 	 * Covers https://github.com/WordPress/gutenberg/pull/31123.
+	 * Covers https://core.trac.wordpress.org/ticket/54515.
 	 *
 	 */
 	function test_child_theme_php_template_takes_precedence_over_equally_specific_parent_theme_block_template() {
-		/**
-		 * @todo This test is currently marked as skipped, since it wouldn't pass. Turns out that in Gutenberg,
-		 * it only passed due to a erroneous test setup.
-		 * For details, see https://github.com/WordPress/wordpress-develop/pull/1920#issuecomment-975929818.
-		 */
-		$this->markTestSkipped( 'The block template resolution algorithm needs fixing in order for this test to pass.' );
-
 		switch_theme( 'block-theme-child' );
 
 		$page_slug_template      = 'page-home.php';