Lloyd Kennewell says the run of Viddora in Saturday's Irwin Stakes was a 'pass mark' and that a bit of bad luck out of the gates was what cost her a first-up win as she progresses toward the Group 1 UBET Classic on May 5.

The star South Australian sprinter was forced to settle at the rear of the field in the Group 3 Morphettville feature and was on the back foot thereafter, but Kennewell is confident she is right on track for her target race. "She just got cut out of the barriers at the start," Kennewell explained.

"It was like the squeeze box at the dogs, she drew barrier three and the horses in two and four jumped inwards, she just got squeezed and spat out the back. She was chasing tail from then on."

Viddora ran home strongly between horses to finish 0.6 lengths off Western Australian raider Dainty Tess, who was able to unleash her turn of foot down the outside and in the better part of the track.

"It was definitely a pass mark for a first-up run, she'll derive a lot of benefit from the run, she had a big blow afterwards," Kennewell said.

"We were disappointed she wasn't able to get two or three lengths closer, the final margin is 0.6 lengths so what happened at the start cost us. I was also bit disappointed with how she travelled from the 600m to corner, I thought she would have bridled up a bit better. But if she settled closer you don't have to work to chase them and she'd be travelling a bit better, it makes all the difference.

"Joe [Bowditch] said she wasn't going good enough to go around them so he had to go in between which was the slow part of the track."

The five-year-old mare will now aim to secure her second Group 1 victory in the $1 million UBET Classic (Sangster Stakes) at her next start.

"She's in good condition this morning," Kennewell added. "She'll have a bit of R and R this week. I'm not ringing the alarm bells at all, like some people are. We know where she is at and I think she'll take huge improvement from yesterday."