Langenhoven produced a best effort of 7.07m, taking the win just two centimetres clear of Azerbaijan’s Kamil Aliyev.
South Africa had racked up two gold medals at the multi-sport showpiece, midway through the third day of competition.
Elsewhere on the track, in the opening round of the men’s 100m T37 sprint, Charl du Toit won his heat in 11.42 to break the world record by 0.04.
Compatriot Fanie van der Merwe finished second in his race in 11.52, with both speedsters progressing among the medal favourites for Sunday’s final.
Ilse Hayes secured victory in her 100m T13 heat in 12.34, also booking her place in the final of her event.
The SA mixed four LTA rowing crew of Shannon Murray, Lucy Perold, Dylan Trollope and Dieter Rosslee ended second in their repechage in 3:36.49, ensuring their spot in Sunday’s A final.
Sandra Khumalo finished fourth in her repechage of the women’s single sculls AS class in 5:59.62, settling for a place in the B final.
Track cyclist Dane Wilson was 10th in the men’s C5 4 000m individual pursuit qualifying race in 5:12.885, and he was eliminated ahead of the medal contest.
Roxy Burns also took 10th position in the women’s 500m C1-2-3 time trial in 45.071.
On the wheelchair tennis court, Lucas Sithole beat Brazilian player Ymanitu Silva 7-5 6-3 in a hard-fought match to progress to the men’s quad semifinals.
Kgothatso Montjane defeated Miho Nijo of Japan 6-2 6-1 to reach the second round of the women’s singles competition.
In the swimming pool, Shireen Sapiro was fifth in her 100m backstroke S10 heat in 1:13.13, missing out on a place in the final.
Alani Ferreira finished fifth in her 200m individual medley SM13 heat in 2:50.43 and was also eliminated.