Originally Posted by
gregman858
Google flights does not have their own booking engine - I was directed back to Delta.com and was able to CONFIRM the lower price.
Which is why I begin 95% of my flight searches with google flights. Like you, I have experienced lower fares for sale on google that DL.com wouldn't offer. Never had an issue booking the lower fare. Just make sure you go into your itin and make sure your upgrades are request (if applicable).
Why does this happen? Who knows. I suspected differential pricing, but have no proof.