Having spent two weeks of her pre-season training program in Doha, Kerber has looked at ease in the surrounds of the Khalifa Tennis Complex all week and required just 50 minutes to brush aside Cetkovska, 61 60.
"I think I was playing well today," Kerber said. "Petra is a great player and yesterday she beat Li Na so I knew it would be tough."
For Cetkovska, who 24 hours earlier had knocked out top seed Li Na, it proved a match too far, as she could find no answer to Kerber's unerring consistency. In her three matches to date, the No.6 seed is yet to drop a set, carrying on the impressive form she produced to lead Germany into the Fed Cup semifinals over the weekend.
"It was a great feeling to get into the semis," Kerber said when asked about her country's Fed Cup win over Slovakia. "We're a great team and it was a great weekend for us.
"I'm just happy to keep playing well here and also that I won in two sets again. I think the year began very well for me but I'm just trying to improve my game with every match and to stay fit and healthy."
Jankovic has been in fine fettle this week, conceding just five games in her opening two matches, and made a flying start against Kvitova, rattling through the opening set in just half and hour.
An early break in the second saw Kvitova gain a belated foothold in the contest, but the respite was only temporary as the Serb came roaring back, taking five straight games to book her place in a third Doha semifinal.
"I'm pretty confident at the moment," Jankovic said. "I've been very focused this week and played very well so far.
"Against top players, like Petra, you have to be at top of your game to have chance to win. I was just sticking to my game plan and luckily it worked. It's nice to be back in the semifinals here."