Kaymer improved from 13th to 3rd in world ranking in 2010 and a top seven finish or better this week will move him ahead of Tiger Woods and into second position behind Lee Westwood.
In cool and at times wet weather, Kaymer birdied five of his first seven holes on day two and added further birdies at the 12th and 14th. Importantly, in the increasingly demanding conditions, Kaymer did not drop a shot and finished day two with a commanding lead.
As a two time winner of this event already and with a game that appears likely to take him to the top of the world ranking ladder before long, Kaymer is already shaping as the man to beat once again.
In contrast, Schwartzel's round was a roller coaster with five birdies and five bogies but, in outright second position, the form that has seen him win in Johannesburg and reel off four consecutive top four results in his last four European Tour events continues.
Like Kaymer, McDowell was a big mover last season and he too has picked up where he left off late in 2010. McDowell has perhaps the advantage of a tournament under his belt already this season having finished a meritorious third at the Hyundai Tournament of Champions in Hawaii two weeks ago and is well placed to challenge Kaymer over the final two rounds this week.
There are still four players to finish round two but to all intents and purposes the cut will fall at even par.
The leading Australasian at present is Richard Green who is in a share of 11th at 5 under, seven behind the lead but only four shots behind Schwartzel. Brett Rumford faltered late in his round but shares 19th position at 4 under, while Danny Lee and Scott Strange are 25th at 3 under.
Much of the talk on day two was of the disqualification of Padraig Harrington who after an opening round of 65 was asked to view an incident during round one where he inadvertently moved his ball when marking it. The ball appeared to Harrington to have only oscillated but a TV viewer saw it differently and under further examination it was deemed to have moved position.
Harrington unfortunately signed for the 65 without adding a penalty and by then it was too late.