AB1: priorities … stuck and need help!

[waterstain]

OK … I've reached the part of level 4 (in priorities) where I get chased by a big, ol' alien down a corridor after it takes down a turret during a cut-scene.

I've tried holding my ground AND sprinting like mad but STILL I get smeared across the floor by the alien with a single swipe.

Could someone help me out with a bit of strategy? Should I be spamming grenades behind me as I run? Do I need to double-back past the alien, somehow?

It's been a while since I last played and I'd really like to get past this point!

UPDATE: Ahh, I kept MISSING a door! Silly me.