His mind went to those he loved - the young Princess Leia and Luke Skywalker. Those thoughts gave him the strength to blast his way out of the rubble using the Force. Able to refocus himself, Obi-Wan swept in for a rematch, and left Darth Vader beaten.
Obi-Wan Could've Beaten Vader in Star Wars: A New Hope - If He Wanted To. While Obi-Wan Kenobi was frail by the time of Star Wars: A New Hope, he was still stronger with the Force than Vader.
Is Obi-Wan Kenobi More Powerful than Darth Vader? There just isn't any way that in an even fight Obi-Wan beats Vader. Although Vader is supposed to be one of the strongest force users of all time, we actually haven't had a chance to see him using his full strength very often.
1/15 Luke Skywalker
Having faced his father once before, Luke was familiar with his tactics and used the force to gain an upper-hand. In Star Wars Canon, only Luke Skywalker can be acknowledged as the one who truly defeated Darth Vader.
Vader held respect for Tarkin which is clearly shown and the only case in which Tarkin outranked Vader would be the case in which Vader was in the Death Star or within Tarkin's Oversector which he likely was as Tarkin was Grand Moff of the Outer Rim Oversector, the largest one.
In Star Wars Legends and Canon, Galen Marek (Starkiller) is the only Jedi (other than Obi-Wan Kenobi) to put a beat down on Darth Vader/Anakin Skywalker. Galen was secretly trained as a Sith Lord apprentice to Vader, but returned to the light side and the Jedi.
Obi-Wan Kenobi's most powerful villains in Star Wars include his greatest enemy Darth Vader and less well-known ones like Darth Krayt.
During his duel with Obi Wan Kenobi, Vader proved to be the superior combatant and was only defeated when he got blinded by rage and hubris, which allowed the calm and composed Kenobi to dismember him. Had Vader managed to keep a clear head and control himself, he would have defeated Kenobi.
As Darth Vader, Skywalker was believed to have had roughly eight-tenths of the strength of the Emperor. Nevertheless, Vader wielded tremendous power and skill, enough to use the Force to overpower almost any opponent he could not defeat with his lightsaber.
Because he was not an active member of the Jedi Order during Order 66, Infil'a escaped execution. Some time later, he faced the Sith Lord Darth Vader wielding a green lightsaber. Infil'a put up a fierce fight against Vader, almost killing him by throwing the Sith Lord off of a cliff.
But this epic showdown ended on an incomplete note, with Vader allowing Kenobi to escape with his life as a wall of fire separated the two characters.
Obi Wan is one of the most powerful Jedi to have ever lived. He is the best defensive duelist in galactic history according to Mace Windu and numerous factbooks. He had a low sensitivity to the force but mastered it to his fullest potential worshiping the force as opposed to bending it to his will.
This information comes to light form the comic series Darth Vader: Dark Lord of the Sith by Charles Soule and Giuseppe Camuncoli, in particular issue #7. Palpatine admits to Darth Vader that the Jedi he actually feared most was none other than Jocasta Nu.
His armor could be hacked and controlled by a device. In a turn of events, Darth Vader's right limb holding his dangerous scarlet lightsaber was moving of its own accord toward his neck. This was a dangerous weakness indeed.
The duel. Darth Vader defeats Darth Maul. The two Sith Lords engaged in a lightsaber duel, going through the volcano and onto a bridge situated over a river of lava, which collapsed, though they both survived and continued their battle.
Obi-Wan was physically struck down in death by Darth Vader in the Original Trilogy. This key moment in the Originals satisfied the question with an answer: in physicality, Obi-Wan may be stronger than Anakin, but Vader is stronger than Obi-Wan.
The only thing his mouth is able to speak is four words: “What have you become?” This is the moment where Obi-Wan is faced with his greatest failure: the loss of his apprentice to the dark side.
Use of the Force
This isn't to say that Mace Windu isn't powerful when it comes to the force. He's on par with Darth Maul and is more powerful than Qui-Gon Jinn. But, Obi-Wan is still the stronger Force user which makes him a powerful combatant.
Anakin Skywalker
Anakin could've been Obi-Wan's greatest ally had he not turned to the dark side, which is the reason why they are fighting again in the new Obi-Wan Kenobi miniseries on Disney+. Thankfully, both characters become friends again at the end of Return of the Jedi.
Did Darth Vader ever lost a fight? Darth Vader is one of the greatest villains of all time. But even he gets beaten sometimes. CBR lists all of the folks who managed this improbable feat!
Return of the Jedi (1983). In the original trilogy, Palpatine is depicted as the Emperor of the Galactic Empire and the master of Darth Vader.
Although Rey has been portrayed as a powerhouse in the franchise, many fans agree that there is no possible way she could defeat Lord Vader. Darth Vader had years of both light and dark side training in lightsaber combat, whereas Rey's techniques are more genetic (albeit impressive for how quickly she learned them).