Raced by Thai outfit Falcon Racing No 7 Stable, the O'Reilly four-year-old has now racked up four wins at his last five starts.
A winner at Class 4 level over seven furlongs at his last start one month ago, On Line was just as lethal when pitted against Class 3 rivals over a trip which connections had been looking to set him on for a while now – 1800m.
Ridden by champion apprentice jockey Simon Kok Wei Hoong, On Line enjoyed an economical run in transit. When the gaps opened up at the 1 1⁄2 f, the bay gelding let down with a short sharp burst with only one horse between him and victory.
After drawing first blood upon straightening as race-leader Buddy Buddy (Ruan Maia) faltered, Japanese galloper Wind Trail (Marc Lerner) still showed plenty of cheek, but was eventually gathered in by On Line with 0 to go.
Three-quarter length separated them with Time Lord (Benny Woodworth) beaten in third place another two and a half lengths away. The winning time was 1min 48.6secs for the 1 1⁄8 m on the Long Course.
Clements saw the win as a confirmation that On Line can run a trip and can also account for better than bread-and-butter class.
"We've been wanting to run him over a distance for a while. He is bred for and everything he's done, he's shown that," said the Zimbabwean-born conditioner.
"It was a god confident ride from Simon. It was quite a soft win in the end as it was not the toughest of fields to beat.
"He's a progressive sort and I think he now has enough points to qualify for the 4YO series. We'll look at a Class 3 race over 1 m next and then run him in the second Leg – we wouldn't want to go for the first Leg."
The Singapore Four-Year-Old Challenge kicks off with the Group 3 Silver Bowl (1400m) in three weeks' time on February On Line will be aimed at the second Leg instead, the Group 2 Stewards' Cup (1600m) on March 20.
The Group 1 Singapore Derby over 1 1⁄8 m is the third and last Leg and will be run on April all part of a major departure from the later June-July time slot for the four-year-old challenge in the past.
Kok opined that such sterner tests would be well within the compass of the NZ$210,000 purchase as a two-year-old.
"He's a very smart four-year-old. It was a big step-up to go from 7 f to 1800m," said Kok.
"He was without blinkers today and he settled nicely for The track had a bit of rain, but he handled it well.
"He's got ability and he's very smart. In future, a step-up in distance will be much better for him."
With a handy record that now reads four wins and three seconds from eight starts, On Line has already gathered more than $170,000 in stakes earnings for the Falcon Racing No 7 Stable.