Goran Ivanisevic demolished Michael Chang on day one of the ATP Champions Tour event in Zurich and then announced that he is to continue coaching World No. 9 Marin Cilic, the 2010 ATP match-wins leader, on a part-time basis.

Ivanisevic, who despatched Chang 6-4, 7-6(3), will travel with the Australian Open semi-finalist to the ATP World Tour Masters 1000 events in Miami and Madrid in a continuation of a relationship that began at the PBZ Zagreb Indoors tournament in February, which Cilic won.

ATP Champions Tour Website

The 21-year-old is coached on a full-time basis by Ivanisevic’s former coach Bob Brett, but in Miami and Madrid Brett will take a step back and allow his old protégé to take the reigns.

“It should be fun," Ivanisevic told the ATP Champion’s Tour website. "Bob is still his coach but in Miami and Madrid I am going to be his replacement while he is not there. I will be like a mentor to Marin.”

It was Ivanisevic who first brought a 15-year-old Cilic to Brett’s attention in 2004, and the pair have worked together ever since at Brett's academy in San Remo, Italy.

Ivanisevic is so determined to win the BNP Paribas Zurich Open this week and then follow up successfully at the inaugural Seguros Bolivar Tennis Champions in Bogota, Colombia, that he has spent weeks practicing with Cilic. He believes it has done the trick - he moved well throughout against Chang and even hit a couple of serves timed at 218km/h (135mp/h).

“I practiced with Marin for a couple of weeks in February and I’m feeling very well prepared for this event. Hitting with Marin has really helped me. I hope the speed gun is accurate here, because 218km/h is good. Hopefully I can go even faster this week. I’ll definitely try. This event is really nice and the court is absolutely perfect as well so I’m really enjoying it here.”