Rosberg has the perfect opportunity to make major inroads into Hamilton's 19-point advantage in the standings. Instead, he came away still trailing Hamilton by nine points
Spa-Francorchamps: Nico Rosberg was handed a much-needed break in the Formula One title battle which he duly converted by winning Sunday's Belgian Grand Prix, but victory could have tasted much sweeter for the German.
Rosberg went into the weekend knowing this was his race to lose.
Mercedes teammate and title rival Lewis Hamilton was set to start at the back of the field after taking a planned series of engine-related grid penalties.
That gave Rosberg the perfect opportunity to reignite his title challenge after a run of lacklustre form and make major inroads into the Briton's 19-point advantage in the standings.
Instead, he came away still trailing Hamilton by nine points after the reigning triple world champion took full advantage of collisions involving his rivals, race disruptions and some spectacular overtaking, to finish a shock third.
"I just saw at the end after the chequered flag I looked at the results and I knew Daniel was behind me and then I see Hamilton in third," Rosberg, who cruised to a comfortable win from pole-position in a chaotic race ahead of Red Bull's Daniel Ricciardo, said.
"I was like 'What, seriously?'. I don't know what happened, I haven't looked at the details, but for sure he must have done a great job."
Rosberg, runner-up to Hamilton in 2014 and last year, opened the season with four wins in the first four races.
He led Hamilton by 43 points following May's Spanish Grand Prix, but has steadily lost ground to his former childhood friend who blitzed to six wins from seven races leading up to the Belgian Grand Prix.
The race at Spa-Francorchamps was Rosberg's one "free race", as Hamilton referred to it, in which the Briton was set to serve his long-pending engine-related penalties.
With the championship now heading to Monza for the Italian Grand Prix, before the Asian leg which Hamilton has dominated the last two years, Rosberg was asked if he had hoped to come away with more from Sunday's race.
"That's not what I'm focusing on," he told reporters.
"I came here, Belgian Grand Prix, and I wanted to win it. So, just happy it worked out, perfect weekend for me."
Hamilton, meanwhile, who now has three new engines, was upbeat.
"Definitely things have happened in the right way in that second quarter of the season and to go into the break 19 points ahead and now only lose 10 today I'll take it," he said.