Power Supply issue?

[Inception9269]

Been having an issue with my pc. Where it's like my Pc abruptly turns off but it turns back on immediately after and loads up perfectly fine.

 

I can use my pc for hours and hours just fine, but if I load up Overwatch for example, I could be searching for a game and right when I find one, my abruptly turns off then back on immediately after. In the last week it happened once, and after I got back into Windows and fired up the game again, it did it again at the same point, once it found a game. It hasn't done that since. Just now however I opened Overwatch and was waiting for a game when it did so again.

 

Am I having power supply issues or something? Once I was in game I mentioned it to the people in the lobby, one of the guys saying he doesn't think so, saying he's had that issue always, him saying he thinks it's a windows 10 issue or something.

 

Thoughts or ideas? I don't have another PSU just lying around that I can try out.