You forgot the to mention the purple flowers and smell of the foliage. Its Glecoma hederacea, the so-called "Creeping Catnip".
no photo of the flower needed. DEFINITELY creeping charlie! i have it ALL through my grass too. it's nasty. it pulls up easy enough since the roots don't go deep. the tiniest bit left will regrow though, so it's almost impossible to get rid of.