Rosberg followed up his Shanghai victory with another commanding performance in the second free practice session for the Bahrain Grand Prix.
The German set that time just over half an hour into the afternoon, ending a busy spell in which the two Mercedes and Red Bull's Sebastian Vettel had been swapping the top spot.
When he set that lap, Rosberg went a full 0.8 seconds quicker than anyone else, and although that margin reduced, no one was able to topple the Mercedes.
Mark Webber ended up second for Red Bull, 0.446s down on Rosberg, and 0.263s ahead of his team-mate Vettel, who had a near-miss with compatriot Michael Schumacher near the end of the session.
Neither car was damaged, and Schumacher completed the day in fifth, a second off his pacesetting Mercedes team-mate.
The seven-time champion was sandwiched between the two McLarens, with Lewis Hamilton fourth and Jenson Button sixth - 0.9s and 1.4s off Rosberg respectively.
Sauber had an encouraging session, as Kamui Kobayashi and Sergio Perez took seventh and 10th, split by Fernando Alonso's Ferrari and Romain Grosjean's Lotus.
Force India's decision not to take part meant only 22 cars ran, with the Silverstone squad's crew instead getting an early start on preparing the cars for Saturday and qualifying before leaving the circuit.
There were myriad minor excursions over kerbs and run-off areas on the still-dusty track, but no major dramas, incidents or problems, with all the cars that ran completing between 25 and 35 laps.