Wasn’t the kid that was killed by the escaped tiger at the San Francisco Zoo last year killed by a paw swipe to his throat?
I will join Huerta88 and Colibri in recommending that if you wish to understand tigers - or simply to read perhaps the best true hunting tales ever written - you should dive into Jim Corbett’s books.
And there is no doubt that the answer to the OP question is yes.
Is this tiger bipedal or quadrupedal?
Because the cause of death is likely to be different.
If bipedal, I would think about a backhander (to push the victim out the way) that crushes the victims trachea. A human could possibly do this, let alone a tiger. This gives a slow, dramatic death (from the observers POV) without requiring deliberate, lethally aggressive action (like using claws) on the part of the killer.
If the tiger is quadrupedal, then you probably have to go with a shove out the way that leads to a terminal injury, or a cuff (to get the victim out the way) with claws that rips open an artery.
My thoughts, anyhow.
Si
I like that you’re worried that your audience might not buy the killed-at-one blow bit, not that they’ll have a problem with the sentient-talking-tiger bit. 
Speaking from personal experience, I can verify that tigers are frickin’ huge.
About ten years ago, me and a couple of buddies went to see a stripper that had a circus-themed act. Part of her act was that she had a tiger that she brought out on stage with her.
Now when you see a tiger in the zoo or in a circus, where they’re a hundred feet away and there’s bars and such between you, they look normal sized. But when you’re looking at a tiger that’s ten open feet away, it looks as big as a house. Its head alone was the size of a volkswagen.
- golf cheer *
Or a blow to the skull, as in Colibri’s quote.
Photos to demonstrate - this where the tiger is standing on his hind legs, and just look at the muscles in the forepaws, and this, with the tiger on his haunches. And he wasn’t quite full grown.
Photos from Dreamland, on the Gold Coast in Australia.
Si
this.
You do NOT play “Slaps” with a Liger/Tigon/Whopping Big Cat, whatever it is!
Although the case of a pissed-off tabby cat causing her owner to bleed out dead from a well placed claw-slashing to the jugular vein (see link below) is most certainly an urban fabrication, the implication is that a pint sized pussy could, in theory, inflict such a mortal wound, if he were so inclined. At 22 lbs., my tabby-striped Main Coon Cat, Tibby (may he R.I.P), though heftier than the average house cat, was a mere speck compared to your average 540lb tiger. So. Translate tubby tabby, Tibby, tearing Tibbytoe’s tonsils to the terminal tube tearing terror tigers threaten (treasure this tortured tight tautogram:cool:…sorry, I can’t help myself sometimes).
Anyway, I believe a tiger—particularly one transcended from mere sentience to cunning sapience—is fully capable of rendering a human adult quickly dead with a single swipe of the paw, via multiple mechanisms of action. For the sake of drama, however, I’d be inclined to choose exsanguination by way of jugular vein transection, even if simply implied.
Of course you play <insert game of choice> with a <insert large, incredibly strong furry creature with aggressive tendencies>.
But you must remember the cardinal rule…
Let the <insert large, incredibly strong furry creature with aggressive tendencies> win
Si
oh yeah, one little shove would do it.