On 29 May the long prepared mine was sprung effectively beneath the "Porepsic". The Spanish then launched a two-pronged assault, one on the breach and the other on the "Polder" bulwark. The Spanish soon crowded into the breach and ferocious fighting ensued. After a long and desperate struggle with heavy losses on both sides the "Porepsic" was at last carried and held by the Spanish. However, the assault on the "Polder" bulwark was repelled and further attempts to take the position were called off.