Under-rated sprinter Mercurial booked himself a ticket to the Gr.1 Sistema Railway (1200m) at Pukekohe with a tenacious all-the-way win over the same course and distance on Saturday.

A ballot exemption for the New Year’s Day feature added extra value to the $65,000 Happy Milestone Birthday David Ellis (1200m), and it was Mercurial who stood up and took advantage.

The five-year-old jumped from the second-to-outside gate in the small field and was sent forward by jockey Craig Grylls to take the lead inside the first 100m. He was soon joined by the high-class mare Bonny Lass, and the pair had the race to themselves from that point on.

Bonny Lass was travelling with ominous ease at the home turn and looked likely to kick away down the Pukekohe straight, but Mercurial rose to the challenge. He eyeballed the $2 favourite and matched her acceleration, and the two went to war in a head-bobbing battle through the final 150m.

Mercurical returned everything Bonny Lass threw at him, and by the time they reached the finish line, the gelding was in front by a head. There was another four and a quarter lengths back to the third-placed Digger, and the race was run in 1:09.48 on a Good4 track.

“I’m rapt with that performance,” Mercurial’s trainer Stephen Marsh said. “He was so determined and tough and got the job done really well. He really rose to the challenge.

“This race carries a ballot exemption for the Railway on New Year’s Day. Coming into it, my thinking was that if he could put his hand up today and be competitive against a good sprinter like Bonny Lass, we should have a crack at the Group One. He’s definitely done that with a very good win, so we’ll press on and run him in the Railway. Why not? He’s earned that opportunity with such a good performance today.

“We don’t have a rider booked for the Railway yet, but I’m hoping a few jockeys might be putting their hands up after that win today.”

By Burgundy out of the unraced Tavistock mare Roxette, Mercurial has now had 24 starts for five wins, nine placings and $199,032 in stakes. He collected his first black-type placing earlier this season with a third behind Our Alley Cat and Not Guilty in the Gr.3 Spring Sprint (1400m) at Hastings.

Mercurial was part of a strong start to Saturday’s Pukekohe meeting for Grylls, who rode the first two winners on the card. He followed up Mercurial’s win with an impressive come-from-behind victory aboard promising three-year-old Mosinvader in the $30,000 Barfoot & Thompson (1600m).