RUGBY LEAGUE: The Warwick Cowboys reserve-grade side will play Souths in a playoff for sixth at 7pm Wednesday at Glenholme Park in Toowoomba.

The winner will play Valleys in a knockout final on Sunday. Warwick secured the playoff after beating Highfields 30-26 on Sunday.

Leaders Gatton beat Souths 26-18 which gave Warwick the chance of a playoff.

On Sunday, Warwick scored in the last five minutes to beat Highfields after captain Brandon Vaughan crossed near the posts.

"I just got there,” Vaughan said.

Vaughan played for Brothers St Brendan's in Brisbane and is captain in his first season in Warwick.

Warwick coach Nick Baker was high in praise of his players after what he described as a tough win.

"The boys got in and dug deep, Darcy Williamson and Greg Hoffman were great off the bench,” he said.

Warwick missed out on the chance of a playoff in A-grade after a 36-20 loss to Highfields.

The score was 8-all after 26 minutes before Highfields scored three tries in 12 minutes to lead 26-8 at half-time.

Warwick fought back to trail 26-20 with 17 minutes to go but Highfields finished the stronger.

Winger Kai Etherington scored three tries for Warwick.

Warwick coach Craig Mullaly said the final 15 minutes of the first half cruelled his side.

"We were getting tired and the three tries hurt,” Mullaly said.

"Our team struck pretty well to Highfields in the second half.”

Darren Pettiford was the best for Warwick.

The Cowboys won the U18 game 20-10 on Sunday and will play South Burnett in a knockout final on Saturday at Clive Berghofer Stadium.