The NSW Waratahs have secured a week off and a home semi-final with a 31-5 win over the Queensland Reds at Allianz Stadium.

Having won the Australian conference before kickoff due to the Brumbies’ loss to the Crusaders earlier on Saturday night, the Waratahs needed to beat the Reds to eliminate the Cape Town-based Stormers from the top-two race.

Michael Cheika’s side came into the match leading the Stormers by two points on the ladder and a loss against the Reds would have given the South Africans a shot at bumping them from second spot in their game against the Sharks in Durban on Sunday (AEST).

The Waratahs came to life in the second half after a dreadful opening 40 minutes, punctuated by penalties and errors, saw the home side leading 3-0.

The game opened up on 50 minutes following the sin-binning of Reds flanker Adam Thomson, with the Waratahs scoring a try soon after when skipper Dave Dennis crashed over for his first try of the season after a lovely inside ball from five-eighth Bernard Foley.

The reigning Super Rugby champions had another five-pointer soon after when Jacques Potgieter opened his account for the season.

Foley was again the provider soon after when he produced another nice inside ball to send replacement halfback Brendan McKibbin under the posts.

Popular replacement lock Dean Mumm then sent the crowd of 26,746 wild when he scored the final try of the game.

Mumm was playing his first game in Sydney after three years playing in England and crashed over from close range.

Quade Cooper scored a late consolation try when he regathered his grubbing kick to score in the corner.

The loss is sure to heap more pressure on Reds coach Richard Graham who lost James O’Connor and James Slipper to injury on a night the Reds said goodbye to stalwarts Will Genia and James Horwill, who will continue their careers overseas.