Rommei then varied his original plan by moving the area of the main thrust from west to east of Knightsbridge to intercept and catch the greatest number of the two British divisions on the northern sector. The advance began at 15:00hrs on 11 June and while 21st Panzer hemmed the battle area of the Cauldron in from the north an encircling group swung towards El Adem. This armoured fist had Trieste Division on the left wing, then 15th Panzer with the two reconnaissance battalions on its right flank, and then the motorised element of 90th Light Division. By 15:00hrs the panzer wave had reached the first objective of Naduret el Gheseauso having encountered only weak British opposition and there Rommel waited for 8th Army's counterattack. But there was no reaction and the advance was then renewed. The 21st Panzer had, meanwhile, driven south of the box at Knightsbridge intending to attack the British armour from the rear. The battle on 12 June did not unfold with dramatic suddenness for both sides were waiting for the other to make a move. Characteristically, Rommel ordered his anti-tank gun line to close towards the British armour daring it to charge and while attention was being held there he sent the right wing of 15th Panzer Division swinging like a scythe blade towards Bir Lefa and the high ground north-west of that place. As the German tanks advanced they were opposed by tanks from 2nd and 4th Brigade and heavy fighting then ensued. At 11:00hrs, three hours after the battle opened, the 90th Light reported that it had reached El Adem and the 21st Panzer, which then came in, struck 7th Armoured Division in the flank. The whole British force was now trapped between the jaws of 15th Panzer closing in from the front and the 21st Division striking from the back. At 14:00hrs the 15th Panzer Division reported that the British from was withdrawing and two hours later announced that Bir Lefa had been taken. By last light the division had reached Point 174 on the Hagiag el Raml by which time 90th Light had attained the high ground north of El Adem. The 21st Panzer Division was given the task of covering the northern flank.
The turning point in the battle came on 12 June; the British armoured fragments had been smashed and 120 armoured fighting vehicles had been lost. The Africa Corps strength return for 11 June had given the number of runners as 124 with 60 more serving with the Italians.
Wireless intercepts indicated that the British armour had been ordered to be offensive west of the remaining boxes and in the dawn light of 13 June the 8th Army's tank regiments attacked southwards but they were seduced into the range of 8.8cm guns and destroyed. The 15th Panzer then went into a counter-attack upon Knightsbridge at 05:30hrs on 13 June but came up short against two belts of mines and remained halted while 21st Panzer, on its left flank, swung along the Rigel escarpment to the north-east of Knightsbridge. Holding position on the ridge were men of the Scots guards supported by South African field and anti-tank artillery. British armour was committed to halt the victorious advance of 21st Division's panzers but they would not be gainsaid and by 17:56hrs could report that the box on Rigel ridge had been captured.
The capture of that high ground made the defence of Knightsbridge box an impossible task and the guards brigade, or rather the remnants of it for its battle had lasted for nearly a fortnight, broke out to join the main body of 8th Army. Ritchie, the Army commander, realised that the victory which he could sense at the end of May had turned to bitter defeat. The Gazala Line would be abandoned and the Army would withdraw and rally before coming on again.
Rommel now had a clear field and flung his forces northward again to trap, within the northern sector, the South African and British divisions at Gazala. The battlefield was tidied en route by the destruction of the box at Eleut el Tamar, taken only after the most bitter fighting. Intercepts reported that the British were moving large bodies of troops from the boxes around Gazala eastwards.
Immediately Rommel ordered that 21st Panzer Division gain the high ground dominating the Via Balbia while 15th Panzer cut the road and held back the attempts to escape. But the opposition put up by British tank forces during the panzer advance northwards had delayed their arrival for long enough to allow the South Africans to begin their withdrawal. The 50th Division faced with blocks on the road east carved their way through the Italian 10th Corps and journeying via Bir Hachim reached the main of 8th Army. Two British boxes, those at El Adem and Acroma, were still resisting the most determined assaults of the Axis troops.
Reports reached Army headquarters at 05:00hrs that South African forces were still moving down the Via Balbia. It was clear that the night drive by the panzer divisions had been in vain. The 21st Division, which had been now cast in the role of pursuing force in the next stage of the Gazala battle, was pulled out of the line and directed upon El Adem where 90th Light and Trieste Divisions were still engaged with the British garrison. The 15th Panzer Division which took over the tasks of 21st Panzer made only slow progress against attacks from both east and west and not until evening was the coast reached. Rommel's plan had been fulfilled.
The tons of stores gathered at points throughout the desert, the half a million mines laid in the Gazala positions, and numerical superiority had proved of no avail against a commander of a force in which armour was used en masse. The British cavalry charges, for that is all they had been, however gallant and however destructive of the German panzers, had failed and now there was only the bitter road eastwards back to the Egyptian frontier.
Spirits in the Axis Army were jubilant. The British had been beaten in the field, their armour dispersed or destroyed, and panzer spearheads were already at El Adem, thrusting deeper and deeper past Tobruk hoping to intercept and catch the 8th Army before it could halt and regroup. German diaries and letters of that time are exultant in tone 'Angriffsziel Tobruk' ('the target is Tobruk') or 'now it is Tobruk's turn were recurrent themes.
Rommel's plan to capture the town was based upon the experiences which he had gathered during the unsuccessful attacks of the previous year and upon a new idea. He would bluff the British into believing that he was pursuing them into Egypt with his mobile forces and then, suddenly he would swing back and attack Tobruk from the south-east with one group, while 90th Light Division carried the attack forward to Bardia. With only a day for regrouping, the Axis forces were ready to continue the battle and an advance was ordered for 17 June upon Gambut. The two German and one Italian panzer divisions moved out against minimal British tank opposition and then fanned out in a race eastwards. The German commentaries on the battle describe how both Rommel and the Africa Corps commander drove the advance forward and how, for as far as one could see, the surface of the desert was covered with tanks and lorries all moving eastwards towards Egypt.
At 18:00hrs at Sidi Maftah the direction of the march changed as the armada swung northwards and Rommel ordered the pursuit to be carried our during the night to reach the sea so that the Via Balbia would be blocked by 18 June. The whole Axis panzer force was spread out, each unit making the best progress it could, while to tha west the remainder of the panzer army had invested Tobruk.
It was not until 16.00hrs on 19 June that the panzer regiments of the Africa Corps moved forward and the hours of waiting had been put to good use by the workshops to carry out the maintenance necessary to keep the vehicles running. Their efforts brought the total of runners with each regiment to between 70 and 75. During the night heavy artillery had come forward into position around the town and the engineer battalion had constructed bridges across which the panzers could pass as they navigated through the anti-tank ditches and defences. The preparations to assault Tobruk had been completed and now only the hours needed to pass until zero at 05:20hrs on the morning of 20 June 1942.