Top seed Nicol outclassed Wee Wern in a gruelling one hour and seven minutes' match with 11-8, 11-5, 7-11 and 11-8.
"In the first two games, I just felt the ball and got my rhythm. In the mean time, Wee Wern managed to get her top form and was moving well. The pace was tight, so I really had to use my strength and take any opportunity there was, to score points.
"I had nothing to lose and she too wanted the national title. I might be too eager at times and made a couple of errors," said the seven-time world champion, who turned 30 on Aug 26.
It was Nicol's third national title after she won it in 2010 and 2011. For her win, Nicol pocketed RM6,000 and a trophy while Wee Wern as the runner-up, took home RM3,000.
Meanwhile, the country's top men's player Ong Beng Hee defended his title after beating Mohd Nafiizwan Adnan in a dramatic and gruelling match.
The 33-year-old Beng Hee encountered a tense match which lasted an hour and 31 minutes before emerging victorious with 11-7, 11-9, 8-11, 9-11 and 11-6.
"When I was leading the match at 2-0, I was thinking about winning the match which I should not do. He started playing very well in the third and fourth game. Luckily, I managed to re-focus in the fifth game.
"I think, mentally, it was very hard. It shows that squash is a tough sport because if you are not focused, you can easily lose the game. I demonstrated that today and that is something which I have to work on," said Beng Hee.
Winning his second national title, Beng Hee pocketed RM10,000 and a trophy.
Mohd Nafiizwan took home RM5,000.
Beng Hee noted that the match was really a tune-up in his preparation for the 2013 CIMB Malaysian Open on Sept 10 to 15, where they have been drawn to play each other once again, in the first round.
"It will be a different condition. I have to really prepare mentally for the Malaysian Open," he said.