Life does not get any easier for Aberdeen Grammar, who slid to their fifth consecutive defeat at the weekend.
Grammar were beaten at home by an organised Marr side which was 17 points to the good in as many minutes.
Grammar assistant coach Matt Reid sid: "We just can't give a side of the quality of Marr a 17-point lead and expect to win.
"Once again our tackling was woeful but there were positives.
"In particular, stand off Sam Knudson is growing into a fine player in a key position, while flanker Jordan Robertson had a good game and is one for the future."
The Ayrshire visitors were quickly into their stride, inspired by brothers Conor and Scott Bickerstaff who scored early tries to set the tone for the afternoon.
Both touchdowns, from the centre and the winger, were converted by Colin Sturgeon.
When the tidy, effective Sturgeon added a penalty in 17 minutes the game looked finished as a contest.
Despite a frenzied spell of activity which led to a home try on the half-hour, Grammar were never able to sustain any dominance over second-place Marr.
The Grammar score was attributed to hooker Conall Howard, who worked hard in the company of fellow front-row players Colin Neilson and Chris Prentice.
Grammar lock Colin Cessford also had a good game, spoiled only by a yellow card picked for dissent just before half-time.
During his enforced absence, Sturgeon added his second penalty to make it 20-5 at the break.
The principal interest in the second half was whether Marr would get a try bonus point after prop Chris Nisbet increased his side's lead with an unconverted try in 50 minutes.
To the home players' credit, they contained the visitors until the last minute of the game when poor defending led to Nesbit grabbing his second try.
Sturgeon failed with the conversion but the try was enough to give Marr a solid win against Grammar, who on this form will not relish a trip to the Borders on Saturday where they meet leaders Jed-Forest.
The only good news for the Rubislaw men is that bottom two - Howe of Fife and Stewart's Melville - have yet to win a game and are nine points adrift of the Aberdeen outfit.
© Jack Nixon
Aberdeen Rugby: Conor Lavery; Grant Walker, Matt Arnold, Kyle McFarlane, Calum Ruxton; Sam Knudson, Jake Gray; Chris Prentice, Conall Howard, Colin Neilson; Aaron Robertson, Robin Cessford; Jordan Robertson, Chris Jollands, Calum Champion.
Replacements: Shane Clark, Fergus McKenzie, Dom Wallen, Andrew Ovenstone, Doug Russell.
Marr: Rory McGee; Scott Bickerstaff, Conor Bickerstaff, Colin Sturgeon, Tom Steven; Greig Kolarik, Grant baird; Chris Nisbet, Stephen Adair, Andrew Acton; Angus Johnston (c), Kris Kirk; Mackenzie Pearce, Kyle Vallance, Ben Johnston.
Replacements: Neil Wallace, Ollie Rossi, Josh Evans, Gregor Ness, Gregor Paxton.