<?php
$svgString = '<svg version="1.1" id="Слой_1" xmlns:x="&ns_extend;" xmlns:i="&ns_ai;" xmlns:graph="&ns_graphs;" xmlns="http://w...content-available-to-author-only...3.org/2000/svg" xmlns:xlink="http://w...content-available-to-author-only...3.org/1999/xlink" x="0px" y="0px" width="225px" height="145px" viewBox="0 0 225 145" enable-background="new 0 0 225 145" xml:space="preserve">
<g>
<defs>
<rect id="SVGID_1_" y="20.387" enable-background="new " width="225" height="104.225"></rect>
</defs>
<clipPath id="SVGID_2_">
<use xlink:href="#SVGID_1_" overflow="visible"></use>
</clipPath>
</g>
</svg>';
$svgObject = new SimpleXMLElement($svgString);
print_r($svgObject->xpath("//rect"));
/* magic */
$svgObject = new SimpleXMLElement($svgString);
print_r($svgObject->xpath('//rect'));
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