While apprentice Koby Jennings has shone at Rosehill with four winners, the star of the show has been the track.

After heavy rain on the eastern seaboard on Saturday, the feature meeting at Eagle Farm in Brisbane was one of many meetings called off.

Rosehill went ahead with the wettest possible rating, a heavy 10, and although it was a race-by-race proposition, the nine-event program was completed.

Sydney's premier trainer Chris Waller, who had two winners, said it showed that the investment in tracks was necessary.

"After the rain we've had, it is great that Rosehill is racing at all," Waller said.

"It shows why we have got to spend money on these tracks so that we can race on days like today."

Marenostro was the first of Waller's winners, living up to his $2.40 favouritism in the FIIG Hcp (1400m) to beat Inz'n'out ($3.10) by 1-1/4 lengths.

It was the five-year-old's ninth win from 25 starts and his seventh on slow or heavy tracks.

"I have a lot of respect for the second horse so this is a good win," Waller said.

"Marenostro is a good horse for this time of year but he does run well on firmer tracks as well.

"There is a 1600 metre race for him in three weeks at Randwick and he should get the right conditions."

While Marenostro was up chasing Inz'n'out throughout his race, stablemate So Willie had to come from last on the home turn to win the Pro It Hcp (1500m) and give Jennings his fourth winner for the day.

Although So Willie had been placed on wet tracks before Saturday he had never won and was a $15 chance with Roguish the $2.90 favourite.

While Roguish was never comfortable, So Willie came up the middle of the track to score a one-length win over More Than Fabulous ($18).

"This is another example of what can be done with track investment," Waller said.

"Horses get their chance from anywhere on the track we have had today."

The meeting was also Marc Van Gestel's first as Racing NSW chief steward following the retirement on Friday of Ray Murrihy.

"It's just great that we got through it and the track held together," Van Gestel said.