How do I complete One is All I Need?

I'm trying to get the 'One is All I Need' achievement but I'm having trouble.

Sometimes get the progress window to pop up, and other times I kill a zombie with one hit and nothing happens. Any hints on best weapons to use and strategies?

Note that you have to kill five Infected in a row: one-hit kills on other types don't count (and also don't affect your streak; the only thing that will break your streak is doing damage to an Infected without killing it).

You're still going to want to do this in an area where there are several Infected; chances are that even if you have a weapon strong enough to one-shot an Infected, if you don't get five at once, that weapon will wear down and not do enough damage later.

Fury is a good option for this: save it until you reach an area where you know there are enough Infected,

say, Chapter 17, where you're trying to reach the roof before White does

and then trigger it. I can't vouch for its success with other characters, but with boosted Fury powers, Sam B tears through Infected easily.

The Dead Island wiki has another suggestion:

There's a cheap way to get this achievement easily early in the game. Near the gas station located in the south of the map in Act I, there is a tunnel with 3 or 4 cars burning. When the player approaches the tunnel, one infected will come out in flames (losing health continually) to attack the player. This wil [sic] make that one simple well-timed blow with any decent weapon will cause death to the infected (as infected have the lowest health among the zombies). About 30 seconds after, one second infected will rush out in the same condition. Repeating this five times will cause the achievement to pop.

Note that this works with Infected who have been damaged. You don't have to take all of their health with one shot, just all of their remaining health.

This was the most recent achievement i got, and I've clocked up almost 48 hours play time. I got it in Act 3 with a modified wakizashi (fully upgraded).

The only thing I could suggest is to find a spot where Infected run at you (the Act 1 mission where you are guarding the mechanics shed, for example), get a fully upgraded bladed weapon and then aim at the head.

Alternatively, you could try setting up gas cylinders on that mechanics mission, and then shoot them as Infected run passed. Don't know if that will give you the achievement though.

It will be hard, and for this reason I ignored it and then got it by chance (running for my life).