AMG Mercedes driver Green, 23, passed early leader Tom Kristensen with a neat move into the Ost Kurve on lap five and disappeared off into the distance to win by 3.696 seconds, a result that elevated him to fourth place in the final points table.
Ekstrom (pictured), meanwhile, ran third for most of the race, ably supported by Abt Audi team-mate Timo Scheider, who did a good job of keeping the Swede's chief title rival Bruno Spengler away from him.
Scheider got his reward as Ekstrom allowed him through with nine laps to go, after both had passed their other team-mate Kristensen, meaning the German finished second - scoring his first DTM podium finish in the process.
Hockenheim II
Rivals gear up for DTM title showdown
11/10/2007 AT 10:29
Ekstrom, 29, rolled in a comfortable third to collect his second title, adding to the one he claimed in 2004 and making him the first Scandinavian driver to win more than one crown in the German-based touring car championship.
After Scheider had done his work early on, AMG Mercedes driver Spengler had an uneventful race to fourth, when what he needed was to finish ahead of Ekstrom.
Fifth and sixth were Bernd Schneider's AMG car and Kristensen, while Persson Mercedes drivers Alex Margaritis and Britain's Paul di Resta completed the points.
Martin Tomczyk, who began the race with a slim chance of beating Ekstrom to the title, was hit by Schneider's Mercedes on the first lap and, after pitting for repairs, could only recover to ninth, ahead of Daniel la Rosa.
Britain's Susie Stoddart came home 14th for Mucke Mercedes, one place ahead of Christian Abt, who was having his final race before retiring, while Britain's Gary Paffett, the 2005 champion, retired in the first lap Schneider/Tomczyk collision.