We know the Greeks won at Marathon.
The Persian expedition set to punish Naxos, Ereteria, and Athens. Let's add Thebes just for the sake of it.
At Ereteria, the locals decided on a siege because no Persian was defeated in a field battle for 300 years unless heavily outnumbered. A local opened up the gates for them, ending the siege.
Let's say at Marathon, the Athenian Left flank and center made holes in their Phalanx when trying to push against the Persians. The first three phalanx lines are compromised and the light Persian infantry plus their cavarly exploit the gaps, killing the more immobile Greeks. The back lines fight on, but they get worn out with the depletion of their front ranks. After an hour, the line collapses and the Persian cavalry start running over
In the end, 3,150 Athenians are captured and another 3K ish are killed. The Persians suffered 1/7 as many losses. They march over to Athens and sack it. An Athenian exile was used as a guide, I'm guessing he stays behind as a puppet? And the Persians crush Thebes, enslaving 3/4 of the able male population and looting.
The Spartan reinforcements arrive close to Athens and defeats Persian scouting force. Seeing the city is occupied by Persians and they were too late, they go home.
Well, the whole invasion force contains 32,000 troops and no siege train. In fact, a TPK on the Persians wouldn't dent their resources manpower or material wise, although the loss of their commanders might be a problem. So what now? They can't possibly hold the whole Greece.
Do they just go home? I mean, they only wanted to add Naxos and Macedonia into their sphere of influence and everything else was a punitive mission.
Did history even change all that much, assuming no ancestors of important people were killed?