Because Maul punched him with the hilt of his saber and then stabs him faster than Qui-Gon can pull back his blade. So Qui-Gon lost because Maul was physically stronger and quicker than him. Qui-Gon is skilled but not a prodigy. And he's quickly worn down by Maul in both their encounters.
The easy explanation was that Qui-Gon didn't use the dark side to sustain himself. He was wounded, and he wouldn't have dreamed of using the dark side to keep himself alive. So, he died of an injury that a dark-sider probably could have survived.
Qui-Gon is one of the most powerful Jedi in the saga: highly skilled in the Force and mastering abilities that other Jedi couldn't, including the ability to consciously manifest after death. But more than his abilities as an individual, it was his maverick philosophy that the Emperor feared.
Seeing his Master murdered caused Obi-Wan to press his attack aggressively, catching Darth Maul off guard. When Maul regained his composure he was able to Force-push Obi-Wan into a melting pit, where he held on for dear life. Calming himself, Obi-Wan leaped over Maul and used Qui-Gon's lightsaber to sever Maul in two.
WHY Did Qui Gon Jinn Lose to Darth Maul in The Phantom Menace? - Star Wars Explained
Who was Darth Maul afraid of?
Regardless, based on the season 7 of The Clone Wars, and the fact that Darth Maul was aware of Anakin Skywalker's future and his role as the Chosen One, it is very likely that Darth Maul indeed feared Darth Vader to some extent, and preferred to avoid a direct confrontation with him, at least, on his own.
During the Invasion of Naboo at the climax of The Phantom Menace, Maul first kills Qui-Gon Jinn, then is defeated when Obi-Wan Kenobi bisects him with a shockingly non-fatal blow.
Master Qui-Gon Jinn's words echo in Vader's mind. There's no anger, nor hatred in this memory – Vader simply recalls one of the first lessons the Jedi Master slyly gave to young Anakin Skywalker.
Dooku, AND Anakin, would be less likely to fall to the dark side if Qui-Gon was left alive and Maul's sympathetic past would never be revealed. For the former, Order 66 wouldn't be executed since Dooku wouldn't be the one planning to do that on the clones.
Qui-Gon Jinn was far from a powerful Jedi Master when it came to fighting. He couldn't even defeat a single Sith Lord's apprentice. He was also the Jedi Master who put too much trust in Anakin Skywalker as his apprentice, which was a proven disaster.
We are led to assume this as in TCW Qui-gon admits his training was incomplete. He could only appear on Mortis, anywhere else he could only be a disembodied voice.
Darth Maul was a greater, stronger and younger swordsman than Qui-Gon Jinn, and more powerful. Darth Maul knew that, Darth Sidious knew that, and for that matter, at the time of their first clash on Tatooine, Jinn himself understood that.
It's already well-established that Qui-Gon was incredibly strong with the Force. He continuously studied the ways of the Force and eventually learned enough about the Cosmic Force and the Living Force to unlock the secrets of eternal life.
He was a wise and well-respected member of the Jedi Order, and was offered a seat on the Jedi Council, but chose to reject and follow his own path. Adhering to a philosophy centered around the Living Force, Jinn strove to follow the will of the Force even when his actions conflicted with the wishes of the High Council.
Qui-Gon Jinn, who is considered a maverick Jedi Master by his colleagues, might have been able to keep Anakin on the path of the Jedi, had he not been killed by Darth Maul. Star Wars' Qui-Gon Jinn would have been the ideal mentor for the young Anakin.
The Council, however, felt Anakin's future seemed clouded and uncertain, and deemed the boy too old to begin training and dangerously full of fear and anger. They refused to allow Qui-Gon to train Anakin, but the Jedi Master nevertheless kept the boy as his ward as he returned to Naboo.
When Qui-Gon was killed by Darth Maul, Dooku was so saddened that Qui-Gon's death lead to Dooku's transformation into the Sith Lord Darth Tyranus. He would later provoke the memory against Obi-Wan Kenobi, Jinn's apprentice.
Though Yoda and Qui-Gon respected each other, they were often at odds due to their differing beliefs; Yoda looked to the future while Qui-Gon lived in the moment.
No. Qui Gon did not speak to Vader in ROTJ. However, it's been revealed that before he died, Bader spoke to Obi Wan, who told him how to become a Force Spirit.
Not only was Obi-Wan tired toward the end of the battle, but Qui-Gon was as well. When Qui-Gon and Maul are separated by a force field, Qui-Gon kneels and rests for a moment—gathering what little strength he had left to try and finish off Maul.
Obi-Wan is good at letting his emotions go. He feels them in the moment, the anger and sadness over deaths of ones he loved like Qui-Gon and Satine. The guilt and pain over Anakin's turn. He feels them deeply, and then lets them go.
Was Obi-Wan Kenobi more powerful than Qui-Gon Jinn? - Quora. Oh, absolutely. Obi-Wan grew exponentially in both lightsaber ability and connection to the force after Qui-Gon's death. He eventually became the absolute greatest Soresu duelist in the history of the Order.
