Lowestoft Town wilted in the intense heat as Royston Town netted the only goal with a quarter of an hour left to play.
Despite there being doubts over several players the Trawlerboys made just one change to the starting line up with Shaun Bammant returning and Miguel Lopez dropping to the bench.
Lowestoft were close to making the perfect start when after just 25 seconds Jack Wilkinson sent in a cross from the left but Bammant's near post header was saved by Joe Welch.
Royston too had a good early chance but with just Luis Tibbles to beat Brandon Adams put his header well wide.
Lowestoft were left cursing the woodwork as Jack Wilkinson's curling cross bounced out off the post.
Play swung from end to end but despite some good approach play clear chances were few and far between up to the break.
Lowestoft's attacking options were reduced at the start of the second period as Reed was forced off to be replaced by Kyle Richardson.
There was another early chance for Lowestoft at the start of the second period but as Jacek Zielonka's corner was met at the far post by Louis McIntosh his header was just the wrong side of the upright.
Tibbles then took centre stage as he saved bravely at the feet of Claudio Ofosu and then from Adams follow up.
Royston then created another clear opportunity but Tibbles again excelled.
Royston were now getting on top and for the second time in three days Lowestoft wilted in the intense heat.
It seemed just a matter of time before the goal came and it duly arrived in the 74th minute.
A left wing corner saw the Trawlerboys struggle to clear their lines and the ball was eventually played low across the six-yard box giving Adam Murray a simple tap in.
Royston should have added a second goal with Adams finding the ball at his feet in front of an open goal but he stabbed wide from less than six yards.
Lowestoft mounted some late pressure but luck was not with them - with Dylan Williams' shot beating Welch in added on time, but it hit the post, spun across the line to hit the other post and be scrambled clear.
Lowestoft Town: Tibbles, Zielonka, Jack Wilkinson, Jarvis, Cole, Deeks, McIntosh (Sub Lopez 70) Fisk (Sub Marcus Wilkinson 75), Reed (Sub Richardson 46), Bammant, Williams, Subs (not used) Tann, Blowers
Royston Town: Welch, Scott-Morriss, Newton, Bridges, Murray, Brathwaite, Crowther, Green (sub Mentis 62), Adams (Sub Newman 88), Bateman, Ofosu (Sub Ryan Ingrey 83), Subs (not used) Dickerson, Castiglione
Referee: Mrs A Byrne
Report by Terry Lynes