Gordon Strachan's side were staring at a second successive defeat in the US until Riordan popped up with a 79th minute equaliser against Chicago Fire.
The former Hibernian man has been touted for a switch to Carrow Road, with the Canaries valuing him at around £500,000 and the Scottish Champions wanting closer to the million pound mark. Whether Grant sees another striker as a priority after the captures of Jamie Cureton and David Strihavka is another matter.