He apparently joined rebels encamped at the foot of Corrigrua Hill, under the command of Father John Murphy (1753?–1798), shortly before the battle of Tubberneering, on 4 June 1798.
Information given to him helped the rebels to anticipate and frustrate the attack of Major-general Loftus and Colonel Walpole.
After unsuccessful attempts to intercept the navigation of the river, Roche moved his camp to Lacken Hill, where he remained for some time almost inactive.
On the following day, he intercepted a detachment under Sir John Moore, who was moving up to join in the attack on Vinegar Hill, at a place called Goffsbridge, or Foulkes Mill, near the church of Horetown.
His disposition of his forces was skilled, but after a fierce engagement, which lasted four hours, was compelled to fall back on Three Rocks, effecting a retreat in good order.