Magnussen again swam his 100m freestyle in a rapid time of just 47.59s to win his race ahead of 19-year-old fellow Australian Cameron McEvoy on the opening night of the five-nation Aquatic Super Series at Perth's Challenge Stadium.
Magnussen was one of 10 Australian winning performances from the 19 events held on Friday with the host nation going into the second night leading the points tally on 327 ahead of Japan (259), China (205), South Africa (163) and Brazil (108).
The Japanese men, outside of Magnussen's 100m freestyle win, were dominant on the night winning five of the nine events not won by the Australians.
However, it was Magnussen's night as he raced home with a second 50 split time of 24.54 to win the 100m freestyle with a time of 47.59 which is only .07 off the time American Nathan Adrian won gold in London with and .04 better than the time he swam himself at the world championships in 2011.
It is the third time in as many weeks that he has gone under 48 seconds and the 22-year-old is delighted with the way his race went.
"It's not too shabby. I'm pretty happy with that one and I think it was a fairly good execution of the race plan. There were a little bit of extra protractions and what not, so I'm pretty happy," Magnussen said.
"I really wanted to focus on my back end tonight. I've been a little bit sluggish since WA so I knew that if I was going to go fast tonight, it was probably going to have to be on that back 25 more than anything."
As happy as he is though, Magnussen knows that in the past he has felt too good about pre-season times and then not been able to deliver on the big stage most notably the 2012 London Olympic Games.
So he is hoping that he can now go even faster in April at the Australian Championships.
"At times in the past I possibly have probably got really carried away with my pre-season times and possibly not executed to the best of my abilities when the big meets have come around. I'm really focused on keeping a level head this year and trying to stay as relaxed as I can," Magnussen said.
"Hopefully it means that I can be going even faster come April, but I think for me it's really important to keep testing myself against great swimmers like I did tonight because that extra pressure and competition makes it a little bit harder."
Meanwhile, the man he beat McEvoy was stunned at the time that he swam while trying to chase down Magnussen.
"I actually felt really good. It didn’t feel like worlds or anything, I felt way stronger than I have there and it's just awesome, and exciting. That's only .31 off my best ever and my best before that was 48.8 so it's very nice," McEvoy said.
"It's awesome having James to race against. We sort of work off each other behind there having a chat about random stuff, and it brings everything down to earth.
"When I was walking out it just felt like any normal local meet because of that, and I think that's what you want and that might have been why we had such good times. That was his fourth 47 this year and that's just insane. He is doing well and it's awesome to see."