Second-half yellow cards for Jack Moorhouse and Ryan Parkinson saw Blues slip to a fourth successive defeat as they lost 41-27 at Blackheath.
Edd Stobart provided a shining light with a superb try double while Frankie Barker sealed the try bonus point with the last play of the match, but it wasn’t enough to prevent defeat.
Director of rugby and head coach Geoff Wappett said: "It was disappointing, almost from start to finish.
"We have a small squad so consequently a few lads have played a lot of rugby and we just seemed to have lost a bit of the zip and intensity we had from a few months ago.
"Our set-piece didn’t function well enough and we had to play almost 20 minutes of the match with 13 men, so in some ways we did well but it wasn’t good enough."
The game got off to a frenetic start as the home side utilised their dangerous backs to race to a 14-0 lead with breakaway tries after 13 minutes, both converted by fly-half Sam Windsor.
Ross Winney got Blues on the scoreboard with a penalty, but Blackheath responded with a third score of their own from Michael Canty.
Charlie Mulchrone, making his return from injury was viciously spear-tackled just before the half-hour mark, which went unseen by the officials.
In the same passage of play Stobart scored his first of the match, touching down in the corner, leaving Winney a difficult conversion but he converted, cutting the deficit to 11 points at half time.
After the break, Blues looked like a different side and began to exert some dominance with a driving maul moving almost half of the field, taking the resulting penalty which left the home side out of position.
Moorhouse made a storming run, off-loading well to Tom Davenport who found Stobart to complete his double.
Blues’ set-piece had been misfiring all match and a penalty for a scrimmaging offence allowed Windsor to restore Blackheath’s lead to nine points.
Moorhouse received the first of Macc’s yellow cards after being adjudged to have prevented a scoring opportunity by obstructing the player from the kick through.
The pressure continued to be exerted by Heath and another driving maul looking destined to cross the line, before Parkinson intervened, which didn’t go unnoticed by referee Tom Foley, sending the flanker to join Moorhouse.
Blackheath were able to take advantage immediately, driving over for a fourth try.
Blues started to defend with gusto, not looking like a side playing with the equivalent of a rugby league side in terms of numbers, not giving the Heath backs anything to work with.
Though both players returned to the fray, the defence finally creaked one too many times and Lee Covington came off the bench to score Heath’s fifth.
Martin Kent came on to shore up the front row and Matt O’Regan replaced Davenport in the midfield.
O’Regan looked very lively early, breaking the line with ease and regularity and almost handed Stobart his hat-trick, but his sharp offload to Moorhouse couldn’t get to the winger.
When Parkinson went over to give his side a slim chance, fly-half Tom Eaton issued a rallying cry to his team-mates.
Despite their best efforts, a pair of late Heath tries put the result beyond doubt but a late touch down by Frankie Barker gave Blues a deserved bonus point with the final play.
Wappett added: "Edd was fantastic today, he couldn’t get enough of everything, and was so, so effective.
"O’Regan looked very sharp and lively off the bench and has done himself no damage for a possible recall next week, as Ealing Trailfinders are another quick side and we will need pace on the field, not watching from the stands."
