Use more resource poisons and procs = win

This is not to mention the passive in the apprentice tree that guarantees your next spell to be a crit after blocking x number of attacks so going ill ham on a sword and board Templar just guaranteed them crit heals

Let's see... in a 1v1 noCP environment? Run me out of resources and you will win. If not that, catch me off guard with huge burst, but no one has really managed that since morrowind so I wouldn't recommend it. You'd likely overextend yourself and have to bail or die for it.

Couple ways to deplete my resources: resource poisons, of course, but if you run those I'll be more cautious which is not what you want. Instead, preparing for a longer fight would be advisable. Obviously, be ready to exploit any mistakes or lapses in judgement I make/have with burst, but other than that, stun me as frequently as you can and compel me to dodgeroll to drain stam. Afflicting me with major defile and then applying some pressure (all packaged nicely in a single incap) will cost me valuable magicka to purge then heal. When I use resto heavies to resto magicka, block the end hit to deny additional regen (If you do that I'll know you're on to me and probably use a potion and play even more cautiously, not good for you. You'd have the upper hand at that point though so use it while you have it). It's very important to not let me, the Templar, control the fight. Lucky for NBs, cloak after a dodgeroll is nearly impossible for me to break, letting you control the fight. Use it so that I don't get a chance to finish a full jab on you. If I can land 2 full jabs on you in a row, you are in deep trouble: that tells me I can burst you without too much effort. If there is a backlash already on you when that happens, your fate is sealed.

Basically, you need to control the fight and get the Templar to overextend himself. It is a tall order, but that's what you have to do. This, though, is from the perspective of a 5/1/1 light armored, full impen dps magplar. Against heavy healbots... don't bother. I certainly don't.

res poisons aren't really all that great against templars. especially with debuff tracking add-ons, good templars will purge them almost instantly. even on a stamplar i can always do that easily.

imho, just like any fight between good players, a 1v1 turns into a longer game of health and resources. some great things to do are: use incap when the enemy has no cc immunity and isn't full life and you (almost) have assassins will ready. follow it up with another attack while he's CC breaking. if you're lucky (or done this well) the templar might have to start burst healing at least one time (often more) before he can find the time to cast extended ritual. thus he's healing himself against a healing debuff and without keeping his dots/pressure up on you. this is VERY inefficient resoruce-wise and a templar that otherwise looked like he had infinite sustain suddenly starts getting low