 When the invaders passed by a small spring called Fontinha, the Jesuit priest Giacomo Rho fired a cannon-shot from the Fortaleza do Monte which landed on a barrel of gunpowder in the midst of the Dutch formation, causing many casualties.The Dutch commanders halted the advance to deliberate their next steps.They decided to climb Guia Hill, upon which a hermitage was situated, to get a better view of the enemy, but their ascent was resisted by a party of 30 Macanese and blacks, whose ferocity and effective use of terrain forced the Dutch to turn back.