A solution leveraging the inferred limit of a 2-digit number in the filename (just because TIMTOWTDI).

use strict;
use warnings;

use Test::More tests => 1;

my @arrayUnsorted = ('page1.html', 'page11.html', 'page2.html', 'page3
+.html');
my @arraySorted   = ('page1.html', 'page2.html', 'page3.html', 'page11
+.html');

my @have = sort { substr ($a, 4, 2) <=> substr ($b, 4, 2) } @arrayUnso
+rted;
is_deeply \@have, \@arraySorted;
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