The Waikato taua came on as far as a place called Waitoetoe on the southern bank of the Mimi River, and there commenced to make a camp preparatory to throwing down the gage of battle. To the watchers in the Okoki pa their fires had been visible for several miles; and when it was seen that they had determined to pitch camp, there was a general request that their position should be at once attacked. Personally, Te Rauparaha preferred to take no risks until the portion of his force which was still holding Tu-korehu in check at Puke-rangiora should have come up. He, however, yielded to the importunities of some of his chiefs, and consented to send out a hunuhunu, or reconnoitring party, to test the mettle of the enemy. To meet the possibility of the skirmish developing into a more serious encounter, he took the precaution of concealing a strong reserve force, composed of the older men, in the bed of one of the wooded streams which ran close beneath the pa. Having instructed Rangiwahia, of Ngati-Mutunga, in whose charge he left these supports, he took eighty of the younger men with him, and advanced across the plain by stealthy marches. So secretly was the movement effected, that they were within a stone's-throw of the Waikato camp, and had actually commenced the attack upon some of the Waikato warriors, before their presence was discerned. In the first onset Te Rauparaha's followers were roughly handled, and, in accordance with their preconcerted plan, they began rapidly to fall back, sustaining severe losses the while from the guns of the enemy. Their retirement soon developed into a general retreat, which might have been much more disastrous but for a fatal division of opinion which sprang up amongst the Waikato leaders, as to whether or not the fugitives should be pursued. Te Wherowhero was content to have repulsed them, and advised resuming the interrupted work of building their shelters; but others, not so cautious, urged immediate pursuit, and, these counsels prevailing, the whole Waikato force was soon in full cry after the retreating scouts. The chase was fierce and stern, and many a good Taranaki warrior dropped upon the plain as he sped towards the pa, for the pursuers kept up as hot a fire as their rapid movements rendered possible. Seeing the men falling round him, a chief who was running close to Te Rauparaha repeatedly urged him to turn and attack the pursuers; but the crafty general, knowing that the time was not yet, declined to forestall his prearranged strategy. He held on his way, only urging his men to faster flight, while Te Wherowhero incited his marksmen to single out the Ngati-Awa chiefs for death. Some two miles of the plain had been covered, and the southern warriors were nearing their supports. As the foremost reached the wooded gully, they waited there to recover their breath, and allowed the pursuers to close in upon them. Weary and blown with their long and exciting run, the Waikatos came straggling up, innocent of the trap into which they had fallen. At the psychological moment Te Rauparaha gave the signal, and out dashed his veterans, fresh and eager for the fray, charging down upon the exhausted and astonished Waikatos. Their chiefs who were in the forefront of the chase were the first to go down, and their numbers were perceptibly diminished as they were beaten back by repeated charges across the blood-stained field. Te Wherowhero fought through the reverse with supreme courage, engaging and vanquishing in single combat no less than five of Taranaki's greatest warriors; and to his fine defence and heroic example is attributed the fact that his tribe was not completely annihilated on the field of Motu-nui. On the other hand, it has been whispered that his companion in arms, Te Waharoa, did not bear himself in this fight with his wonted gallantry. Waikato paid a heavy toll that day. They left one hundred and fifty men dead on the field, and the slaughter of chiefs was a conspicuous tribute to their bravery – Te Wherowhero and Te Waharoa being the only leaders of eminence to escape.
For some inexplicable reason, Te Rauparaha did not pursue his victory to the bitter end, as was his wont.54 This forbearance on his part is especially surprising in view of the fact that Te Wherowhero had specifically promised to remain neutral during the progress of the migration. Possibly the consciousness that he would have done the same thing himself induced him to take a lenient view of his old antagonist's want of good faith; for there can be no doubt that the bloody wars which were at this time ravaging the country had completely sapped the old Maori sense of honour. "At the period in question, more perhaps than at any other in the history of the race, moral considerations had but little weight in determining the conduct of either the individual or the tribe. Even the nearest relatives did not hesitate to destroy and devour each other." There was thus nothing unusual about Te Wherowhero's conduct; but his experience of Te Rauparaha on this occasion was such that from that day onward he left him severely alone.
The effect of these successive victories was to enhance enormously the prestige and power of Te Rauparaha. He began to be regarded with reverence by Ngati-Awa and with something akin to worship by Ngati-Toa. As a tangible proof of the gratitude which his hosts felt for the services which he had rendered them, food, which had been grudgingly supplied up to this time, was now given in abundance to his people, and, what was of even greater moment to Te Rauparaha, adherents began freely to flock to his cause. But, although he had beaten off both the Ngati-Mania-poto and Waikato tribes, the position was still unsatisfactory to him from the point of view of numbers, and so he resolved to make one more effort to persuade Ngati-Raukawa to join him. Accordingly he journeyed back to Opepe, a village on the shores of Lake Taupo, where he met young Te Whatanui, a chief destined to become famous in after years as the protector of the Muaupoko people whom Te Rauparaha wished to destroy. Upon the assembled tribe, and upon Te Whatanui in particular, he again impressed the merits of his scheme, pointing out the altered position occupied by the tribes who had managed to become possessed of fire-arms, as compared with those who had only wooden spears and stone meres. He dwelt upon the fact that ships were beginning to frequent Kapiti, and that there they could obtain guns, as Nga-Puhi had done at the Bay of Islands. He also reiterated all that he had formerly told them about the fertility of the soil and the ease with which the country might be conquered: but in vain. Te Whatanui volunteered no sign of approval. He gave many presents to Te Rauparaha, as marks of respect from one warrior to another. He also made him a long oration, skilfully avoiding the all-important topic upon which Te Rauparaha had travelled so far to consult him; nor did the majority of his people conceal their objection to coming under Te Rauparaha's immediate command, to the exclusion of their own chiefs. Angered at this perversity, Te Rauparaha shook the dust of Opepe from off his feet and proceeded to Rotorua, and as far as Tauranga, where he sought the aid of the great Te Waru. But he met with no success, for Te Waru had schemes of his own which claimed his personal attention. While resting with the Tu-hou-rangi branch of the Arawa tribe on his return to Rotorua from Tauranga, Te Rauparaha (according to accounts) perpetrated an outrage upon Nga-Puhi which was destined to inspire one of the most disastrous wars and one of the most daring assaults known in Maori history. His motive for "sowing the seeds of evil counsel" is not clear. By some it is alleged a jealous envy of Nga-Puhi's success in procuring arms, while others find it in the consuming desire for revenge for the death of a young relative killed a few weeks before at the fall of the Te Totara pa at the Thames. Whatever the motive, before leaving he took occasion to recite a karakia, or song, informing the Tu-hou-rangi that there was a small band of Nga-Puhi travelling about in their vicinity, and broadly insinuating that "death and darkness were very good things." This hint, however enigmatical, was taken and acted upon. When Te Pae-o-te-rangi, Hongi's nephew, and a company of his Nga-Puhi followers arrived at the Motu-tawa pa, from which Te Rauparaha had just departed, they were treacherously set upon and killed by the Tu-hou-rangi people. It was to avenge the death of Te Pae-o-te-rangi that Hongi performed the Herculean task of dragging his canoes from Waihi, near Maketu, to Lake Rotorua, and on the island of Mokoia slaughtered the unfortunate Ngati-Whakaue (Arawas), who had been entirely innocent