Who won in Star Wars: Revenge of The Sith, Yoda or Darth Sidious ?

Yoda had the upper hand throughout the majority of the fight. He won the lightsaber duel part of the fight, and even after Palpatine was trying to get away. Yoda had the upper hand but was forced to flee.

Yoda was more experienced. He could have won if it was just a wasteland. Notice that Sidious didn't even want to fight him close at the end. He was throwing the senate whatever boomerangs at him.

Just like I said Yoda is way more experienced than the sith lord. He would have taken him down. If Mace Windu could so could Yoda.

Yoda won the majority of the battle.

Yoda. He disarmed Palpatine of his lightsaber and forced him to retreat despite being in a tight area in which the acrobatic moveset of Ataru couldn't be execute it to the fullest potential. Even with gravity helping him, Yoda still matched him blow for blow with him only falling because he was much lighter than Palpatine. Yoda only retreated because his very exhausting fighting style left him already fatigued and climbing the senate pods a second time would have likely exhausted him to the point that by the time he reached Palpatine and dealt with all the clones (who in that same movie could kill Jedi blademasters), he wouldn't have much fight left in him and Palpatine could take advantage of that. Palpatine might have surpassed him after RotS but even that is very debatable so I'm gonna go with Yoda for now. If the fight took place in An open arena then Yoda would win with mid difficulty, he'l I bet Anakin or Obi Wan could have beaten this version of Palpatine in a strictly lightsaber duel. Even Daisy Riddly of all people knows who is superior between Yoda and Palpatine! Ask my friend @Tyrannus for evidence that Yoda was "demoralized" during that fight and couldn't focus which would mean Yoda would be even more powerful than Palps.

They stalemated. But if they kept going I think Yoda.

Darth sidious