Veteran Max Biaggi (44), meanwhile, extended his own record as the oldest rider ever to stand on a World Superbike with a solid third in Race 1, only to crash out in Turn 1 of the second race.
Superpole winner Tom Sykes on the second factory Kawasaki grabbed the hole shot and set a blistering pace, leading for the first 11 laps and shattering the lap record, before his tyres cried enough and he gradually dropped back to finish fifth, while Rea and Ducati rider Chaz Davies battled it out for the lead.
On the final lap the leaders were pushing each other to limit at every turn, so much so that Rea ran wide on the very last corner, but was able to use the unusual width of the Sepang circuit to get on the gas early and hold on to take his 12th win of the season by a nail-biting 0.121sec.
Biaggi came home a lonely third to claim his 71st World Superbike podium, well ahead of Pata Honda’s Sylvain Guintoli, (his best finish of the season so far) and Sykes.
Alex Lowes was sixth on the factory Suzuki, ahead of Aprilia Team rider Leon Haslam, privateer Ducati team-mates Matteo Baiocco and Niccolo Canepa, and Jordi Torres on the second works Aprilia, who dropped from what looked like a safe fourth to 10th in the final few laps.
In a mirror image of the earlier race it was Davies who tried to make an early break, with Rea chasing him all the way, after a turn-one incident that saw Biaggi go down, while Sykes and Lowes had to take avoiding action.
The result was in dispute until the very last corner as Davies and Rea banged fairings, literally side by side – but Davies had the inside line and held on to take his thirds win in four races by just 0.091sec and move up into second in the championship standings with 308 points to Rea’s 452 - a difference of 144 with six races, worth 150 points, to go.
Sykes and Lowes rejoined the action in 14th and 17th respectively, and proceeded to cut through the field until Sykes crashed out of eighth on lap six - effectively ending his championship challenge for 2015 – while Lowes continued on to finish eighth.
But even then Sykes remounted and soldiered on to bring the battered Kawasaki home 14th and salvage two heard-earned points.
Aprilia factory rookie Jordi Torres put in a fine ride to claim his second podium of the season, well ahead of Guintoli, who posted another fourth on his best weekend of the season thus far, and Pata Honda team-mate Michael van der Mark, making up for his Race 1 retirement with a solid fifth – a scant tenth of a second ahead of Aprilia lead rider Leon Haslam.
Kawasaki privateer David Salom, Lowes, Baiocco and Roman Ramos (Kawasaki) made up the rest of the top 10.
POINTS AFTER 10 OF 13 ROUNDS
Honda privateer PJ Jacobsen became the first American to win a World Supersport race a after a race-long battle with Jules Cluzel’s factory MV Agusta.
Championship leader Kenan Sofuoglu (Kawasaki) was first down to Turn 1, only to outbrake himself and run wide as the next six riders dived through. By the end of lap one, however, he was back up to fifth as he set about reeling in Jacobsen and Cluzel, who had already begun to pull away from the pack.
By half distance he’d bridged the gap and joined the leading pair - which meant the top three riders in the series standings were all in contention for the race win – but Sofuoglu catch-up ridfe had asked too much of his tyres and he gradually fell back in the closing stages, until he was demoted to fourth by Lorenzo Zanetti on the the second works MV Agusta at the very last corner.
Jacobsen held his nerve despite intense pressure from Cluzel to take his maiden Wor;d Supersport win by less than a tenth of a second, with Zanetti and Sofuoglu even closer together in third and fourth, three seconds later.
Pata Honda’s Kyle Smith finished a lonely fifth, well clear of veteran Roberto Rolfo (Honda), while Martin Cardenas (Honda) got the best of a three-way battle with his privateer Honda team-mate Gino Rea and Kawasaki rider Christian Gamarino, and Alex Baldolini (MV Agusta) rounded out the top 10.
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Original source: WSBK wins for Rea, Davies at Sepang