By Alan Baldwin

LONDON (Reuters) - Nico Rosberg drew level with Damon Hill in Formula One's all-time list of race winners on Sunday and the odds are narrowing on the German matching the Briton again as the only sons of world champions to take the title.

Hill, the 1996 champion and son of late double title-holder Graham, currently stands alone with that achievement but maybe not for much longer.

Even if Mercedes team mate Lewis Hamilton remains the bookmakers' favorite to take his fourth title, Rosberg is increasingly fancied after retaking the championship lead with six races to go.

"While Rosberg has the advantage on paper, we think Lewis Hamilton is still favorite but only just," commented William Hill spokesman Joe Crilly.

Malaysia, next up in two weeks' time, could swing the balance further towards the German who has won all three races since the summer break and eight -- out of 15 -- this season.

He is eight points clear of Hamilton, the first time he has led the standings since July, and reaching new levels of performance.

"I've known Nico since 2013 and that is the best Nico Rosberg I have ever seen throughout the weekend since then," declared Mercedes motorsport head Toto Wolff. "He was just blindingly fast."

The German is already a Formula One phenomenon, holding an unwanted record that he hopes to shed -- that of the most successful driver not to win a championship.

He took that from Britain's Stirling Moss, who won 16 grands prix and was four times overall runner-up in the 1950s.

No driver has ever won eight races in a season and not taken the title, even if there are a record 21 this year, so that would also be a first if he fails to prevail.

Rosberg, whose Finnish father Keke took the 1982 title and won just five Formula One races, already has more victories to his name than 19 champions.

His 22 puts him level with Hill, whose father ranks some way behind on 14.

One more would put Rosberg level with triple champion Nelson Piquet of Brazil, two would equal five-times champion Juan Manuel Fangio of Argentina.

By the end of the season, if he continues the streak, he could have passed Niki Lauda, Jim Clark (both 25) and Jackie Stewart (27).

Finns have already hailed Rosberg as their most successful driver -- the German-born Monaco resident has a Finnish passport -- since he overtook double champion Mika Hakkinen and 2007 winner Kimi Raikkonen (both 20 wins).

Rosberg made more history in Singapore on Sunday when he became, in his 200th career start, the first non-champion to win that floodlit race since it joined the calendar in 2008.

"What a weekend, crazy stuff," he said. "It just all came together really well...

"Singapore hasn't treated me all too well in the past years, especially 2014 breaking down on the start whilst I was in the championship battle. So to get the win here was also extra-special."

(Reporting by Alan Baldwin, editing by Pritha Sarkar)