The seriousness of the situation in which the British had been now placed was not at first realised and, indeed, did not become apparent until both panzer divisions began to roll up 7th Armoured Division from east to west. For the assault 21st Panzer Division took the right flank with Belhamed as its objective, while 15th Panzer Division on the left moved via Sidi Muftan towards Sidi Rezegh. The wide, armoured front of the two panzer divisions advancing side by side and followed closely by the batteries of 8.8cm guns, moved rapidly forward and drove before it scattered British units which it encountered. By midday the heights south of Sidi Rezegh had been reached and 7th Brigade's commander, appreciating the sudden danger, broke off his own attack and swung his force to meet the onrushing panzers. The defence of Sidi Rezegh airfield was then passed over to Support Group. The British tanks observed the panzer force passing across their front and firing from hull-down positions struck deep into the German flank. Once the shock of the first contact had passed a general melee developed and bitter battles were fought out between tank and tank, and tank and guns. Before long the British had settled down, had taken up all around defence against the Germans, and had prevented them from seizing the airfield. During the afternoon tanks encountered German trucks as they were replenishing their fuel and ammunition stocks and attacked these causing much panic and alarm. Night fell and the fighting tailed off leaving only the burning vehicles to illuminate the blackness of the night. The opponents drew back from each other. The two panzer divisions tired from the strain of fighting and of night driving, hoped to laager for the night but then came orders for them to change their positions and 15th Panzer Division was moved to Gambut while 21st Panzer Division proceeded to Zaafran.
During 21 November the pressure upon the Italians at Bir el Gobi had forced the Italian Corps commander to bring forward elements from Trieste Division from its position around Bir Hachim and to counter the advance of the Indian Brigade, on the deep southern flank, Rommel ordered his only available force - planes of the Luftwaffe - to bomb the Indian vehicles. On the far eastern front the New Zealand division reinforced by more than a hundred tanks struck across the Trigh Capuzzo.
The situation on the evening of 21st was that a link-up attempt by forces within and without Tobruk had failed, but only just, and that day was the first high point of the British offensive. Only at the last gasp could the attack towards Tobruk be halted by the Africa Corps striking for the first time in that offensive in a unified movement. The panzer mass between two British tank brigades had the opportunity to defeat these separately before either British Corps could intervene and by evening the important high ground in the area of Belhamed was again in German hands and formed a line from which future operations could proceed.
Nevertheless, in view of the serious difficulties with supply columns and a shortage in tank ammunition Rommel was compelled to order that for 22nc the Africa Corps would go over to the defensive. Rather surprisingly Corps did not act upon that order but to an earlier one which had given instructions to regroup. The two panzer divisions then moved out: 15th to a point south of Gambut and 21 st descending from high ground, reached the line Belhamed-Zaafran, north of the Trigh Capuzzo.
That night supply columns once again had difficulty in finding their units but had reached them during the morning and the panzer force began to fill the empty shell racks with ammunition and the empty petrol tanks with fresh fuel. During that day a serious situation developed when it was realised that the depots around Tobruk which had been laid out to supply the investing forces had also been drawn upon to provision, refuel, and re-arm the attacking units and that this double drain had completely exhausted the stocks. In future the haul would be to depots farther back in the rear areas and would take not only more time but consume more fuel, and the convoys would be, over the longer route, more vulnerable to British air assaults.
At Sidi Rezegh the 4th and 22nd Brigades had fought their way through to the aerodrome and 5th South African Brigade, forming the spearhead of 1st South African Division, had struck out from Bir el Gobi into the flank of 155th Regiment defending Point 178, but against determined resistance it could only gain ground at a slow pace. During the morning both sides took the opportunity to regroup and the British who were ready first re-opened the battle by resuming the break-out attempts from Tobruk and combining these with armoured assaults launched towards the town by 7th Armoured Division. All these furious sorties were beaten back and in the ensuing lull the panzer divisions once again began to refuel.
During the afternoon of 22nd Rommel decided to take up the offensive once again and this move produced for the Germans the conditions for the opportunities, which were to be presented in the following days, of attacking the flanks and rear of the British forces.
Rommel placed himself at the head of 21st Panzer Division and led an armoured phalanx towards Sidi Rezegh. With artillery support and with the flanks of his advance protected by 90th Light Division, the panzer group struck down from the north. The 5th Panzer Regiment on the Axis road, south of Tobruk, drove towards El Duda in a two battalion box formation with 2nd Battalion in the van, reached the Sidi Rezegh aerodrome, and then turned eastwards. The panzer attack met the fighting vehicles of 7th Armoured Division; large and fierce tank versus tank battles were fought around Sidi Rezegh. Under German pressure 7th Support Group was slowly driven back from the airfield ajid late in the afternoon it began to withdraw southwards to link up with 7th Armoured Brigade. To support its sister brigade, the 22nd Armoured then thrust up from the south in a desperate counter-attack but the gallant advance was held by the front, while panzer forces swung round the British flank and smashed the brigade. Throughout the short, winter afternoon the battle raged but at last light the panzer drive thrust through the 22nd Armoured Brigade and, having knocked out 45 from a total of 80, scattered the remainder, leaving the British unit now only a rump to withdraw upon the main of 7th Armoured Division.
During the afternoon Rommel had compounded the British defeat by flinging the 15th Panzer Division from its positions around Sciafsciuf into the 7th Armoured Division's rear eastern flank, where was located much of that unit's weakly defended 'tail'. The heavy blow, carried out at top speed, met very little opposition as British soft-skinned trucks and isolated tank groups from 8th Hussars and 4th Brigade were surprised, overrun, or dispersed. This scything sweep cost the British units 35 tanks, the whole of the armoured car strength and all the guns.
Suddenly, or so it seemed, the tables were being turned and Rommel had in a few short days destroyed at least half of 7th Armoured Division's armoured force: had smashed 4th Armoured Brigade, had beaten off the assaults of 22nd Armoured Brigade, had flung back the assaults out of Tobruk, and had decimated through air attack the Indian Brigade advancing on the southern flank. Against this tally of victories the single British success had been the capture of some positions on the Sollum front and the westwards advance by the New Zealanders against determined opposition put up by 3rd Reconnaissance Battalion on the Via Balbia and by 33rd Armoured Reconnaissance Battalion along the Trigh Capuzzo.
The total successes claimed by Panzer Army Africa during the four days of the fighting had been 207 British tanks destroyed and to this total must be added the 50 claimed by the Italian Motorised Corps. The strength of the British tank brigades had been savagely reduced - only 10 runners were with 7th Armoured Brigade, 22nd Brigade had only 40, and there was a further handful with 4th Brigade.