Konev’s forces captured the Korsun airfield on 13 February, abruptly terminating the Luftwaffe airlift. It was clear that Gruppe Stemmermann could only last a few more days. On 14 February, as a desperate expedient, Luftwaffe Ju-52s flew low over his tanks and dropped drums of petrol in the mud, most of which burst. Bäke received just enough fuel to make a small advance, but he could not reach the pocket and he was stopped by intense enemy resistance on Hill 239. That day, the thaw ended and it began to snow again, which hardened the ground. Kampfgruppe Bäke and Kampfgruppe Frank sparred with Bogdanov’s armour near Lisyanka, claiming another 19 T-34s from 5 GTC and some Shermans from 5 GMC, but four Tigers and three Panthers were damaged. With ammunition and fuel nearly exhausted and barely 20 tanks still operational, Breith’s relief effort ground to a halt at Lisyanka on 15 February. Vatutin simply ordered Bogdanov to place more tanks and anti-tank guns to bar any further advance, while the remainder of his forces and Konev’s reduced the pocket. One of the units that arrived to reinforce the 16 TC was Polkovnik Nikolai S. Grishin’s 13th Guards Heavy Tank Regiment, equipped with 21 IS-1 (IS-85) heavy tanks, equipped with the same 85mm D-5T as the KV-85. These heavy tanks were committed into action on 15 February and unwisely attacked Kampfgruppe Bäke instead of sitting on the defence; the Panthers and Tigers knocked virtually all of them out. Following this incident, the GABTU resolved to upgrade the new IS-series heavy tanks to the 122mm gun.
Finally recognizing that relief would not arrive in time, Stemmermann resolved to conduct a breakout operation on the night of 16–17 February to reach III Panzerkorps. In order to gain a springboard for the breakout, Stemmermann launched a series of night attacks from 11–13 February which captured the towns of Shanderovka and Nova Buda from the besieging 27th Army. Attacking at night wearing winter camouflage uniforms, the German infantry caught the Soviet trops by surprise and succeeded in getting a bit closer to III Panzerkorps at Lisyanka. During the day, Konev attempted to retake these towns, but Wiking’s last tanks and assault guns, led by SS-Sturmbannführer Hans Köller, fought them off and defended the breakout assembly areas.{17}
Kampfgruppe Frank and Kampfgruppe Bäke made one last push to Oktaybr on 16 February, destroying part of another Soviet tank brigade but losing more Tigers and Panthers in the process. Frank’s Panthers encountered KV-85s from the 13th Guards Heavy Tank Regiment, attacked to the 16 TC, which was an unpleasant surprise.{18} Gruppe Stemmermann’s lines were 7km away. Stemmermann’s breakout began at 2300 hours on 16 February and initially went quiet well, as infantry from the 72.Infanterie-Division infiltrated through the Soviet cordon, which was held by elements of 5 GTA. However, the Soviets soon detected the breakout and all hell broke loose as the night sky was lit by flares and artillery fire. Wiking tried to break out with 11,500 troops, seven tanks and three assault guns, but was engaged by Soviet tanks and anti-tank guns. Although the combat troops maintained some semblance of discipline, many of the support troops panicked and scattered, or caused traffic jams with the vehicle columns. Stemmermann was killed in the stampede and Soviet cavalry appeared out of the woods to cut up the rear echelons. Thousands of German troops reached the Gniloi Tikich River on foot and were forced to cross this obstacle, which ended up with hundreds drowned or frozen to death. Soviet tanks fired into the horde at the river’s edge, causing further panic. In the end, 35,199 Germans managed to flee the Korsun pocket and reach III Panzerkorps, but about 19,000 were killed or captured.{19} Gruppe Stemmermann abandoned all its artillery and vehicles in the pocket, including 20 tanks and 30 assault guns. Wiking lost over 3,000 men in the breakout and took six months to refit.
The relief effort cost the German Panzer-Divisionen involved dearly, with III. Panzerkorps and XXXXVII Panzerkorps suffering a total of over 4,000 casualties. Breith’s III. Panzerkorps lost 156 tanks and assault guns during the relief effort and was left with only 60 tanks and six StuG IIIs operational. Approximately 56 per cent of the losses were due to mechanical defects, particularly with the problematic Panther (at least 15 of 37 lost in III Panzerkorps suffered engine problems and were destroyed). Indeed, on 29 February 171 of the 187 Panthers in PzAOK 1 were under repair. Von Vormann’s XXXXVII Panzerkorps had lost about 80 tanks and assault guns and was left with 32 operational tanks and 27 assault guns. The combination of muddy roads and limited recovery vehicles meant that when the relief forces retreated to new defensive lines, many non-operational tanks were blown up rather than allowed to fall into enemy hands. In order to save part of five trapped divisions, von Manstein had expended his armoured reserves.
At one stroke, Vatutin and Konev had removed two corps from Heeresgrupe Süd’s order of battle and incapacitated most of the German armour in the Ukraine, which made it virtually impossible for von Manstein to hold any kind of frontline. In the aftermath of Korsun, von Manstein was primarily focused on shoring up the left flank of Heeresgruppe Süd held by PzAOK 4, which was holding a 240km front with 12 depleted divisions. The gap between Heeresgruppe Süd’s left flank and Heeresgruppe Mitte’s right flank was only screened by the XIII Armeekorps, which failed to prevent Vatutin’s 13th Army from seizing the cities of Rovno and Lutsk on 5 February. Indeed, there was little from preventing Vatutin from driving due west into Poland. However, von Manstein’s right flank was also on the verge of collapse. The transfer of the 24.Panzer-Division to support the Korsun relief effort had weakened the German defence of the Nikopol bridgehead at a critical moment. On 2 February, Malinovsky’s 3rd Ukrainian Front attacked the left flank of Hollidt’s AOK 6 east of Krivoi Rog and quickly achieved a breakthrough that the Germans lacked the armoured reserves to block. Within 24 hours, the Soviets captured the vital rail junction at Apostolovo and threatened to isolate the IV and XVII Armeekorps in the Nikopol bridgehead. Hollidt was forced to abandon Nikpol on 7 February and retreat westward to avoid encirclement. Even when the 24. Panzer-Division was returned to Hollidt, it had lost most of its tanks and 55 per cent of its trucks in the fruitless march north to join the Korsun relief effort.
Meanwhile, the Soviets were able to replenish the 1st and 2nd Ukrainian Fronts within two weeks of the end of the Korsun battle and Zhukov was eager to press on and finish off Heeresgruppe Sud before it could be reinforced. However, Vatutin was badly wounded by Ukraininan partisans on 28 February and died six weeks later; Zhukov temporarily took command of the front. The loss of Vatutin was a serious blow to the Red Army since he had become one of its most skilled practitioners of combined arms warfare. In comparison, Konev and most of the other front commanders tended to rely more on firepower than manoeuvre or deception. Zhukov immediately began preparing for the next round and using his clout with the Stavka, he managed to acquire the 4th Tank Army (6 GMC, 10 GTC) from the RVGK; this formation was under the command of General-leytenant Vasily M. Badanov, who had led the Tatsinskaya Raid in December 1942. In addition, Zhukov was able to get replacements for the 1 TA and 3 GTA, although neither could be brought up to full strength.