A tearful Brian Smith has a warning for his rivals after the trainer turned back the clock 41 years to win his second Grand Prix Stakes (2200m) at Eagle Farm.

Order Again ($4.20) hit the lead at the 300m and held on to beat Volatile Mix ($9) by a nose, with 1-3/4 lengths to Violate ($18) in third place in the Group Three race on Saturday.

Smith won the Grand Prix in 1976 with the champion Balmerino but declined to tackle the Queensland Derby with him and instead won that year's Brisbane Cup.

But it will be a different tale this time, with Order Again headed to the Derby on June 10, where he will try to become the 14th horse to win the Grand Prix-Derby double.

Smith has had his share of problems with Order Again this campaign but has nursed him to the middle distance races.

"I have tears in my eyes not because I am crying but because they are tears of relief. I have had my problems with this horse but I have never lost confidence in him," Smith said.

"The future is very bright for him and the Derby will be the first step. When you get to my age (76 years), you treasure getting a good horse."

Order Again was bred and is owned by the Stewart family, who also had Smith's Brisbane Cup winner Jetset Lad.

Smith feared winning jockey Larry Cassidy might have gone too soon.

"Brian tells me to count to 10 and maybe went on eight. It could have even been a quick seven-eight but you have to go some time," Cassidy said.

The favourite Shocking Luck ($3.60) came sixth after not looking comfortable in the straight.