In the demographic for people aged 25-54 - the target demographic for TV3 and TV One - Campbell Live had 127,600 viewers compared with 99,100 for Seven Sharp.
In the 18-39 age group, Campbell Live had 55,500 compared with 40,800 for Seven Sharp. The audience for people aged over 5 years is an indicator of the total audience, which is dominated by TV One.
Media commentator Brian Edwards said the ratings were not a reflection of Seven Sharp's content on Tuesday night.
"It was actually the best it's been since it started. The figures are a result of an accumulation of seven or eight programmes that people just thought really weren't very good."
Mr Edwards said the shift between channels was a major development.
"In all the years that John's been on, they weren't able to achieve this and now they have."
Tuesday's ratings are significant, with Seven Sharp providing the most accomplished performance so far, however fewer people would have seen the signs of improvement in the show.
Mr Edwards said changes in the show indicated that producers had taken into account criticism it had received over the past week.