The latest Rajar radio audience listening figures for the last quarter of 2014 show that Kiss grew its reach by 5.9 per cent on Q3, while Capital lost 6.5 per cent of listeners in the same period.
Global-owned Capital's 1.87 million weekly listeners also represents a 13.3 per cent slide on the same quarter last year, while Kiss gained 4.8 per cent year on year.
Capital's overall downturn is mirrored in its breakfast figures, as the 6am-10am slot hosted by Dave Berry and Lisa Snowdon was the only one of the big four London stations to take a hit to its morning listeners.
The pair pulled in a weekly audience of 941,000, falling 6.6 per cent on the previous quarter, and dipping below the one million mark for the first time since the first quarter of 2014, although still winning the most breakfast listeners in London.
Meanwhile, more than 870,000 people tuned into the Kiss breakfast show in the final three months of the year, up 2.6 per cent year on year from 689,000 in Q3.
And despite sitting in third place overall, Heart London pulled in an extra 23.1 per cent of listeners with a weekly audience of 1.78 million, up from 1.45 million in Q3.
The increase also means 14.5 per cent growth since the final three months of 2013, while the station’s breakfast show with Jamie Theakston and Emma Bunton made up some of the ground it lost in the previous quarter by winning an additional 160,000 listeners, taking their audience to 681,000.
Meanwhile, Magic showed the biggest quarterly dip, losing 10 per cent of its audience between quarter three and quarter four as figures fell to 1.76 million from 1.96 million.
However, year on year, the Bauer Media-owned station stayed pretty stable, adding 0.4 per cent to its reach.
And the loss of the breakfast DJ Neil Fox – who was dropped after his arrest on 30 September following allegations of sexual assault – hasn't affected the station's morning audience, as it grew 13 per cent period on period to 884,000 in the final quarter of 2014.