A perfect end to a momentous day for Checa, the result also signals a return to glory for Ducati in the manufacturer's standings, the Italian marque having now won 17 trophies in 24 years.
Just as he did in the first race, Laverty began to struggle in the closing stages, with the fast-approaching Marco Melandri getting the better of him on the final lap with a robust pass at Adelaide. The Italian had enjoyed a fairly stealthy ride up the order after a slow start, the future BMW rider sealing his second podium of the day.
Despite losing out to his team-mate, third for Laverty means he has now assumed the same position in the WSBK standings, ahead of the absent Max Biaggi, with one round remaining.
Following his run to third in race one, a fourth place finish for Leon Haslam signals his best points' haul as a BMW rider, while Sylvain Guintoli kept up the pressure on Leon Camier in the overall standings by passing the Briton on the final lap for sixth.
Joan Lascorz reinstated himself as the top Kawasaki rider in the standings by claiming seventh place, ahead of BMW duo Ayrton Badovini and Troy Corser, while Haga slipped back to tenth after struggling in the second half of the race. Javier Fores and Maxime Berger completed the finishers in 11th and 12th.
Elsewhere, there was more disappointment for Michel Fabrizio, who suffered a second crash of the day, while Mark Aitchison lasted only three laps before pulling out having suffered in his race one accident. Jakub Smrz didn't make the grid, meaning just 17 riders started.