Tuesday's tariff delay helped the rand "make an aggressive move" from R15.39/$ to R15.16/$, said TreasuryONE in a snap note.
The additional 10% tariff on some $300bn worth of Chinese imports was set to be implemented on September 1. 1 "based on health, safety, national security and other factors".
Other products whose tariffs will be delayed until December 15 include "computers, video game consoles, certain toys, computer monitors, and certain items of footwear and clothing", the USTR said in a statement.
Earlier on Tuesday, China's chief trade negotiators, Vice Premier Liu He and Commerce Minister Zhong Shan, spoke to their U.S. counterparts, Treasury Secretary Steven Mnuchin and Trade Representative Robert Lighthizer. Shares of Apple, Mattel and shoe brand Steve Madden shot up.
A 4.8% jump in Apple shares and a rise in chip stocks pushed the technology sector, traditionally among the most sensitive to trade issues, 2.33% higher. The Philadelphia chip index rose 3.16 per cent.
However, some consumer electronics items spared from previous USA tariffs on Chinese goods, including smart watches, fitness trackers, smart speakers and Bluetooth headphones, were not given a reprieve.
Additional details and lists of the specific product types affected by the announcement are due to be published by USTR later.
The dispute between the world's two biggest economies has rattled financial markets for more than a year and clouded the global economy.
U.S. President Donald Trump on Tuesday cited China for not following through with expected large purchases of U.S. agricultural products but appeared hopeful that Beijing's stance could change.
"Trade talks are continuing, and during the talks the USA will start, on September 1st, putting a small additional tariff of 10% on the remaining 300 billion dollars of products coming from China into our country", he tweeted at the time.
But in a tweet on Tuesday, Mr Trump hinted that he was expecting something in return, suggesting that China's failure to "buy big" from United States farmers could be about to change. "Maybe this will be different!"
The Dow gained more than 400 points, or 1.7%, rising to 26,339 at 10:40 a.m. The Nasdaq Composite was up 165.16 points, or 2.10 per cent, at 8,028.57.