K-1 World Grand Prix 2006 in Auckland. After three rounds, Aerts was given the majority decision (28-28, 28-28, 29–28) win over the giant karate fighter. This win proved that, while his performances against top-tier competition had been waning in recent years, he was still a world-class kickboxer. In his next fight, Aerts faced fellow K-1 legend Ernesto Hoost (the fifth and final meeting between the pair) at the K-1 World Grand Prix 2006 in Amsterdam on May 13, 2006. The circumstances surrounding the match were rather bizarre as Hoost was scheduled to face Bob Sapp that night and Aerts was only there to commentate for television. However, Sapp ran from the Amsterdam ArenA and Aerts stepped in to replace him, and had to borrow a pair of fighting shorts from Semmy Schilt (which had Schilt's name written on them and displayed the Golden Glory gym's logo). Despite having not trained for the fight, Aerts was still able to last all three rounds with Hoost and lost a majority decision (30-29, 30–28, 30-30). Then, following a knockout win over Hiraku Hori at the K-1 World Grand Prix 2006 in Seoul in June and a decision victory against Gary Goodridge at the K-1 World Grand Prix 2006 in Sapporo in July, Aerts faced Musashi in a tournament reserve fight at the K-1 World Grand Prix 2006 in Tokyo Final on December 2, 2006. He defeated Musashi by first-round KO, and after Remy Bonjasky was forced to withdraw from the Grand Prix due to an injury, Aerts took his place and met Glaube Feitosa in the semi-finals. After knocking the karate man down with a barrage of strikes in round two, the referee stopped the fight and Aerts went through to the final where a rematch with reigning champion Semmy Schilt awaited. He was unable to reenact his March 2006 performance, however, and Schilt took a unanimous decision (30-27, 30–27, 30–28) after three rounds. Schilt knocked him down with a knee in round two and dominated the fight overall with his size advantage. On June 23, 2007, at the K-1 World Grand Prix 2007 in Amsterdam, Aerts faced Bob Sapp in a much-anticipated superfight. In what was a rather anticlimactic affair, Aerts struck Sapp with the left knee, Sapp fell down and the fight was over in 0:25 of the first round. He then KO'd Nicholas Pettas with a sensational high kick at