I tried running for it during the gas/temple part, but always ran out of stamina before reaching the doorway and getting cut down. After a few tries, here's how I finally beat it:
From the edge of the gas, start picking off the first few enemies hiding behind fallen columns (these guys do NOT respawn). When they're all dead, move up to the broken column in front of you and pick off a couple more. When there are only 3 enemies left (at the doorway - these do respawn), throw a grenade as far forward as you can, and start sprinting. While running near enemies, fire a round or two to stun them, and/or throw another grenade. When they're all stunned, just book it to the doorway.
It's not as hard as people say. Just make sure to start picking off enemies at the very edge of the gas, where there's cover on the right side. Also, be careful because there will be 1 or 2 enemies attacking from behind, which you should also kill.