$re = '/ (?=\d{1,2}:\d{1,2})/m';
$str = '46:28 Corner, Switzerland. Conceded by Walter AyovÃ. 46:26 Attempt blocked. Stephan Lichtsteiner (Switzerland) left footed shot from outside the box is blocked. Assisted by Granit Xhaka. 45:00][Second Half begins Switzerland 0, Ecuador 1. 45:00 Substitution]
';
$subst = "\n";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php