Bohemians too have now emerged as a dark horse in a surprisingly lively Premier Division title race, a hard-fought win at Dalymount Park showing how far Bohs have progressed in recent weeks.
A goal from Georgie Kelly decided a captivating encounter, with Rovers regretful that they or in particular Rory Gaffney spurned a scatter of chances in the first half. That one was theirs but the second was clearly Bohs' and it was no great surprise that they found a way to edge their bitter foes in north Dublin.
Quite incredibly, Rovers' form since they broke the league record for a sequence of unbeaten results has given everyone else hope: their last seven league games yielded wins only over lowly Longford (at the death) and Waterford, with defeats suffered against Dundalk, Sligo and now Bohs, arguably the form team in the league.
Conditions were pretty much perfect at Dalymount, though the pitch rather betrayed the recent hot weather, with plenty of yellow to augment the green. The image of those substitutes wearing green climbing into their positions in the Jodi Stand emphasised that Stephen Bradley's squad remains a little stretched, with a scatter of young players in reserve. Coach Bradley has never been afraid to promote teenagers in big games.
Bohemians' bench looked considerably stronger, but could they do it on the pitch? With ten points separating the teams going into the game, their title challenge, if one exists, was perhaps hinging on getting a win here.
Unsurprisingly, Bohs welcomed back Keith Buckley, Gary O'Neill starting again for the visitors. There was a lot at stake; midfield would be critical.
Rovers had a great chance on eight minutes. Sean Gannon hooked the ball into the box and, despite Rob Cornwall protesting that he had been fouled by Rory Gaffney, the Galwegian was allowed to strike at goal from a matter of yards, but he blazed the ball over. Bohs again rode their luck big-time a minute later, with Gaffney's shot defleted off the woodwork when it looked certain to go in after a loose Rory Feely clearance.
If this were to be Bohs' night, they were riding their fortune, and they had further encouragement on 13 minutes when a late tackle from Lee Grace saw the Shamrock Rovers defender carded.
However, Gaffney was again in on 15 minutes and this time he did little wrong, prompting a superb save down to his right from James Talbot. Incredibly, Gaffney was through three minutes later from a nice Danny Madroiu pass but he made a total hash of an intended assist to Graham Burke when selfishness may have served him better.
Bohs created next to nothing in the first half hour but Liam Burt did flash an effort wide at the Des Kelly end on 28 minutes.
Even the 100 or so fans allowed in as Ireland makes a glacial return to normality made a difference here, gleeful mocking of a slack Mandriou pass reminding the Dubliner that his departure from the Gypsies is not forgotten. Ten minutes shy of the break, Ali Coote tried to deceive Alan Mannus at his near post from a difficult free-kick position but the ball curled wide.
Bohs took the lead 11 minutes into the second half. The league's top scorer Kelly, who had barely had a crumb of a chance hitherto, turned Pico Lopes confidently and finished brilliantly beyond Mannus after a Burt pass.
Talbot is arguably the best goalkeeper in the league and again he was technically top-class to bat away a Mandriou stinger shortly after the opener. In Rovers' next attack, this time Talbot stretched low to his right, denying Graham Burke, who was hugely influential.
Conscious that both were carded, Chris McCann and Grace had both been taken off by Bradley in the third quarter. Mandroiu, who had a fine game, would rather have wished other than to fall over in front of the Bohs' fans as he chased the ball and the game.
Georgie Kelly was in again midway through the half but delayed a little and Rovers cleared. It looked as though there would be plenty of chances yet in this absorbing derby.
Gaffney seemed offside with ten minutes left but the flag stayed down and Burke's strike was saved by Talbot, arguably the man of the match.
Tierney left the arena to a standing ovation in injury time, a testament to another tireless effort from the kid from Ballymun, who recently scored for Ireland's under-21s. Bohs were comfortably able to close out the game and have developed into a very good football team. That is what Shamrock Rovers are too but the formality that many thought was their title challenge seems less predictable at this stage.
Wait until the crowds return.
Bohemians: Talbot; Feely, Cornwall (Finnerty 86), Kelly, Wilson; Devoy, Buckley, Burt (Ward 80), Coote; Tierney (Levingston 90); Kelly.
Shamrock Rovers: Mannus; Hoare, Lopes, Grace (Green 64); Gannon, McCann (Finn 54), O'Neill, Mandriou, Scales; Burke; Gaffney.