And WIN is claiming victory over its rival among the younger viewers TV advertisers prefer.

But Bruce Gordon’s Wollongong-based broadcaster has also been the biggest loser in the prime-time ratings since changing channels from Nine to Ten on July 1.

The first official ratings results since regional TV’s big free-to-air switcheroo show WIN sliding from second to fourth place overall in major markets - behind the ABC.

Free-to-air audience data for the month of July shows Network Seven affiliate Prime7 is No. 1 in southern NSW and  Victoria with all-people network shares of 27.1 per cent and 38.3 per cent, respectively.

In southern NSW, which includes the ACT, Wollongong, Wagga Wagga, Orange and Dubbo, WIN’s network share of 6pm-midnight viewing has slipped almost five percentage points.

When it was showing Nine programs like The Voice over the first half of 2016, WIN averaged 25.1 per cent.

Since its switch to showing Ten programs like Shark Tank, WIN has averaged  a 20.5 per cent share.

Southern Cross Austereo, which snatched Nine’s content from WIN in a $500million deal, has increased its share of the evening audience in southern NSW - from 16.8 per cent when it showed Ten’s shows, to 22.6 per cent in its first four weeks as the Nine affiliate.

But while WIN has grown the audience for Ten’s content - to 20.5 per cent from 16.8 (up 3.7 percentage points) - Southern Cross Austereo’s audience for Nine content is so far falling short of WIN’s share when it was the Nine affiliate.

In the Victorian TV market, which includes the centres of  Bendigo, Ballarat and Albury/Wodonga, WIN averaged 17.1 per cent of the 6pm-midnight audience over its first four weeks showing Ten’s content, down 5.5 percentage points from its 22.6 share over the first half of 2016 when it was Nine’s regional partner.

Meanwhile, Southern Cross Austereo’s relay of the Nine signal had 19.0 per cent last month, an improvement on its 15.5 share as the Ten affiliate this year but short of WIN’s performance when it carried Nine’s shows.

WIN’s performance in July was boosted by the final weeks of MasterChef, with episodes of the cooking show accounting for WIN’s six highest-rating programs in southern NSW and its three top shows in Victoria.

The most-watched program overall in southern NSW was the third State of Origin rugby league clash, the first not telecast on WIN for decades, which drew 256,902 viewers to Nine.

In Victoria, the climax of Prime7’s House Rules was July’s top show, with 194,557 viewers for the winner announcement episode.

WIN’s switch to a five-year program supply agreement with Ten - struck after Nine ended its 30-year association with WIN to partner Southern Cross Austereo - has also affected audiences for WIN News.

WIN’s flagship local news bulletins averaged 53,714 viewers a night across southern NSW in the new 6pm timeslot - between  Ten Eyewitness News First at Five and The Project.

By comparison, WIN News had 77,049 viewers over the first half of 2016, when it aired at 7pm after National Nine News.

The audience drop has been even sharper in Victoria, where WIN News has averaged 46,117 at 6pm - down from its average of 85,940 viewers over the first half of the year when it was WIN’s top-rating show.

WIN chief executive Andrew Lancaster told Fairfax Media  he was not concerned that Prime7 had claimed victory in the 6pm news timeslot in the last week of July in his company’s home town of Wollongong.

“We’ve moved our news into a different timeslot and we would expect that would have caused some disruption to viewers,” he said.

WIN News won back the timeslot the very next week, with Mr Lancaster describing the 6pm news contest as “a marathon not a sprint”.

While a slide in prime-time ratings risks a slide in revenue, WIN is preferring to focus on the lucrative younger audiences it says Ten programming like The Bachelor is now delivering.

Across the five states where it now carries Ten, which also includes Queensland, Tasmania and Western Australia, WIN claimed victory over Southern Cross Austereo’s Nine content among viewers aged 16-39, 25-54 and 16-54.

WIN’s calculations show it closing the traditional gap between Nine and Ten programming and growing the audience for Ten shows by 14.7 per cent across the five states, while the Nine content’s 6pm-10.30pm audience share has declined by almost 21 per cent.

“The results speak for themselves,” Mr Lancaster said in a statement.

 “We’ve closed the gap and done very well in the three key demos with our Ten programming beating Nine programming.”

Mr Lancaster said WIN was “thrilled with our partnership with Network Ten”.

“This first month has shown how well the programming connects with our audience and provides a solid base for our continued growth throughout the year.” 

WIN has also been bouyed by last week’s figures showing that Ten’s share of free-to-air TV advertising revenue is up - largely at the expense of Nine, which has slipped to its lowest share in four years.

WIN owner Mr Gordon is the biggest  shareholder in Ten, which recently installed Mr Lancaster on its board.

But the new data from industry body Free TV also reveals that the overall TV ad market from January to June this year had its biggest drop in revenue since 2011, and its worst first half of a calendar year since 2009.

The total market across Seven, Nine and Ten was worth $1.739billion over the six month period – down 4.3 per cent on the same period a year before.

Regional TV revenues fared even worse, down 5.69 per cent.