Defeat ten enemies in a row with a single punch, after softening them up with gunfire.

To get a Steel Fist kill you have to first injure an enemy with enough gunfire (without aiming with L1), and then hit them once by pressing the square button. To get this trophy you need to do that ten times in a row. This means if you kill someone with just gunfire, you have to start over. A great place to do this is in Chapter 4 on Very Easy difficulty. You first have to kill the first set of enemies and then trigger a cutscene. Right after the cutscene, you will be shown how to use grenades in the game, and during this tutorial, you will kill an enemy with the grenade. Right after you do that, you can go for this trophy.

Like the video will show you, one shot with the .45 Defender (without aiming with L1) followed by a punch (square button) on very easy is enough. The advantage with doing this on very easy is that you can take a lot of gunfire without dying. Be selective with your enemies and be sure to avoid enemies that are close together. Just ignore them and keep moving around until you find an enemy by himself. Then just shoot without aiming and punch him with the square button. Then continue to move around and do this with 9 more enemies. If you do a mistake and kill an enemy in another way, just hit start and choose Restart Checkpoint. If you can't avoid people close together, pay attention to which person you shoot. You will see small drops of blood spraying out of the enemy you shoot. Look at the video below for a demonstration.