Kaiser Sun has tested the training talents of Mat Ellerton and Simon Zahra.

But with back-to-back wins at Flemington, the lightly-raced sprinter is showing signs his talent is being harnessed and he is starting to fulfil his untapped potential.

Kaiser Sun faces his biggest test yet at Flemington on Saturday when he shoots for his third straight win this campaign in the Listed Kensington Stakes (1000m).

The four-year-old gelding has had soundness issues and has been hard to handle on the training track with Ellerton previously describing him as "a mad bolter".

Zahra, who trains in partnership with Ellerton, said Kaiser Sun was starting to relax better with racing under his belt and they had worked out the best way to train him.

"He's been a hard horse to train and do everything with but he's now just starting to relax on the track and with those runs under his belt he's not as fierce," Zahra said.

Kaiser Sun scored an all-the-way win over 1000m at Flemington at his first start for seven months on December 14.

He then was able to sit just off the lead over the same course and distance on New Year's Day and was successful again, taking his record to four wins from six starts.

"We were rapt with the way he sat off that horse the other day and relaxed and then he quickened," Zahra said.

"He hasn't done that before so it was good to see him do that, and that way he doesn't become one-dimensional where he has to lead at all costs.

"He'll probably learn from that again and he's going up another cog so he's got to improve mentally and physically."

The Kensington Stakes has attracted 17 nominations headed by the Anthony Freedman-trained First Command who has won the race for the past two years but hasn't raced since his unplaced effort in last February's Lightning Stakes.

He is topweight with 60kg ahead of General Truce on 59kg.

Zahra said Kaiser Sun, who has 54kg, would not have been entered unless they thought he would be competitive in the Listed feature.

"Also it's going to give us a guide to see where he's at as well," he said.

He believes going into the race third-up on the back of two wins over the same course is ideal.

"He loves the straight and still probably comes in well-weighted," Zahra said.