With just three rounds remaining this season, including Sepang, Pedrosa trails his fellow Spaniard Lorenzo by 28 points following his impressive win in Japan as the Honda rider picks up crucial points for the title bid.
Nonetheless, Lorenzo's lead effectively means he can be assured of the title by finishing at least third in the last three races regardless of what Pedrosa secures.
Pedrosa now has 282 points against 310 for Lorenzo.
The Motegi win was Pedrosa's second consecutive victory after taking Aragon in September, and his fifth this season. He was a former 125cc and two-time 250cc world champion.
It will be a very emotional return to the Sepang track, where the late Honda rider Marco Simoncelli lost his life during last year's October 23 race.
Riders would on Thursday pay homage to Simoncelli and are expected to put on a tremendous display of motorcycle racing to honour the flamboyant Italian.
Pedrosa is on a roll, though he likely needs to win every remaining race in order to stand a chance at taking the championship.
With 75-points still on offer, Lorenzo is looking strong but seems unable to hold Pedrosa's fast pace.
The Mallorcan however has said he will go to Malaysia to win.
Razlan Razali, Sepang International Circuit CEO told AFP he expects a tough race in possible wet track conditions.
"Pedrosa will aim for a strong win to further slim Lorenzo's lead and keep his title race alive," he said.
The long Sepang circuit is physically demanding and a wet track would make the race challenging as it is noted for its sweeping corners.
Razlan said the return of Australian Casey Stoner, who won here in 2007 and 2009, would add to the excitement and help organisers attract the target 70,000 spectators on race day.
"There will be no holding back. The riders will go all out to win. It will be a fantastic race," he said.
Lorenzo, Pedrosa and Stoner have won all the 15 races out of the 18 among themselves so far.
Stoner, who has 197 points, missed three races this season after injuring his right ankle in qualifying at the Indianapolis Grand Prix. He returned last weekend at Motegi and plans to retire at the end of this season.
Lorenzo missed last year's Malaysian Grand Prix race due to injury where 24-year-old Simoncelli was killed in a second lap crash. The race was subsequently cancelled.
Razlan said at the memorial event, riders would walk towards turn 11 to pay their tributes before a bronze plaque.
Sepang will be followed by the Australian Grand Prix at Phillip Island on October 28 and with the season ending race at Valencia on November 11.