Both teams were players short due to university holidays, but the absentees affected Roslyn more than Caversham, and that situation was aggravated even more when Patrick Ebanda was sent off by Invercargill referee Craig Campbell after nine minutes.
Ebanda slammed on a tackle at the edge of Roslyn's penalty area that possibly merited a yellow card, but referee Campbell rated the situation as denying a goal scoring opportunity, and Ebanda went for an early shower.
Andrew Ridden scored the first of his two goals after 16 minutes, as Caversham mounted repeated attacks against Roslyn's 10 men.
Sometimes an extra man advantage means little, but Caversham's ability to switch play wide, and expose space on the wings, had coach Colin Thom's Roslyn side struggling.
Seamus Ryder powered up one side, and Sam Collier attacked on the left, with marauding runs by Tom and Lewis Jackson slicing through and testing the tackling ability of centre backs Tyrrell Barringer Tairi and James Watson.
The return of Tom Connor from Auckland injected pace and threat, but too often the final pass let Roslyn down, while Caversham's percentage passing kept pressure on the visiting team.
Despite the pressure, Roslyn still found energy to counter attack, and from a right wing foray by Ben O'Farrell, the youngster launched a speculative shot from distance and hit the jackpot as the ball skipped past keeper Darryl Putt to equalise in the 21st minute.
But it was a short lived respite, and Roslyn soon had its back to the wall again as Caversham ran well off the ball, and had the skills to switch play and deliver crisp passes that pulled defenders out of position.
Goals by Collier and Lewis Jackson created a 3 1 lead at the break, and, all things considered, 10 man Roslyn would not have been unhappy at that margin.
After an hour, Ridden finished a good move to stretch the lead to 4 1 and once again Roslyn put up the shutters, defended with spirit, and still chased a goal to get back into the game.
''Then we had a nightmare patch during the last 10 minutes,'' Roslyn coach Thom said.
''Possibly legs had gone with the earlier effort, but we drastically lost our shape, and Caversham scored four late goals within six minutes to earn a depressing 8 1 win.''
Caversham's Tim Horner said that his team stuck to its task and kept up the standards he expected. The coach was pleased with good performances by substitutes Will Smith and Ryan Fleming.
Another huge scoreline in Timaru had Dunedin Technical win its Chatham Cup tie 10 0 against Northern Hearts.
Hat tricks to both Tim McLennan and Aaron Burgess, and two goals to Josh Stewart broke Northern Hearts. Andrew Douglas and John Curwen also scored and a provider par excellence, Ross Howard, engineered six assists that led to goals.
At Memorial Park, University showed grit and defensive nous to hold Mosgiel at bay for most of that Chatham Cup tie and after 90 minutes only one goal separated the teams.
Fielding a stronger team this week the students were hard to break down, and had their share of the play. Mosgiel midfielder Eder Franchini crashed a close range shot against Varsity's crossbar, but a well worked corner saw Riley Anderton flick on, for Rahan Ali to score Mosgiel's winner.
