Rosberg, who started on pole, was never seriously threatened and crossed the line 4.9 seconds clear of Red Bull’s Max Verstappen, who fended off a late-charging Lewis Hamilton after the Briton recovered from a woeful start to finish third.
Rosberg extended his lead over Hamilton to 33 points in the overall standings following his ninth win of the season and with four rounds remaining, the 31-year-old can claim a maiden title without needing to win another race.
Hamilton went into the race searching for a Suzuka hat-trick to revive his flagging championship prospects after being forced to retire from the lead at the last race in Malaysia but his chances of victory were dashed within a matter of seconds.
The Briton was unable to capitalize on his front-row start as he crawled off the line and found himself languishing down in eighth place by the time he reached Turn One as his Mercedes team mate disappeared over the horizon.
Once he had recovered from the disappointment of the tardy start, a mix of his trademark spectacular overtaking and clever strategy by Mercedes saw him scythe through the field and very nearly snatch second from Verstappen. Unable to get enough speed from his drag reduction system (DRS) to pass the Dutch teenager on the home straight, Hamilton had to settle for third after he ran wide on the penultimate lap attempting an audacious pass at the final chicane.
Ferrari’s Sebastian Vettel, who started sixth due to a three-place grid penalty for shunting Rosberg at the start in Malaysia, did well to finish fourth but his hopes of a podium spot were compromised late on by slow moving back markers.
The German got off to a fantastic start and looked competitive in third but after losing touch with Verstappen and getting passed by Hamilton on his second pit stop, a bold tire strategy failed to pay off for Ferrari.
His Finnish team mate Kimi Raikkonen, who started eighth after collecting a five-place penalty for an unscheduled gearbox change, also complained of track-hogging back markers on his way to a fifth=place finish.
Daniel Ricciardo, winner in Malaysia a week ago, was sixth in his Red Bull as Force India pulled further ahead of Williams in their private battle for fourth overall.
Sergio Perez and Nico Hulkenberg finished seventh and eighth ahead of Felipe Massa and Valtteri Bottas, who struggled for pace all weekend but made the most of a one-stop strategy to salvage some points. – Reuters