The Terriers were defending a slender one-goal lead thanks to Sean Scannell's neat first-half finish when Smithies kept out City defender Stephen McManus' late header with a fine reflex save to ensure a 1-0 victory for his side and help Huddersfield bounce back from successive defeats.
"In the end we were indebted to Alex for making a couple of good saves," said boss Simon Grayson.
"They were throwing bodies forward in the closing stages and Alex showed how good a goalkeeper he is by keeping his concentration levels high and making the save from Stephen McManus."







