Shaak Ti wins each time.
She was completely superior to Galen Marek in every aspect, as confirmed in the novel.
She was so fast he could barely keep track of her, she was on top of him and injuring him with strength stated to be equal to his own and was throwing Kinetite balls 'cuz **** Sith that's why.
The novel, the highest form of canon in regards to TFU states very clearly that Shaak Ti had him undoubtedly beaten, dominating him even, only a last minute innate TK reflex saved his skull from being cut in half, he also just managed to angle his blade through her gut without even realizing it.
This is the same Galen Marek that is earlier in the same novel stated to be blocking direct blows from Darth Vader in a sparring match that would destroy a Jedi Knight, showing that his defensive abilities were excellent. Making Ti's trashing him in a duel all the more impressive.