Sukhoi Su-33(USSR) ✈ Shenyang J-15 (China)

Sukhoi Su-33(USSR). First flight: 17 August 1987 (WIKI)

Shenyang J-15 (China). First flight: August 31, 2009 (WIKI)

An unfinished Su-33 prototype, the T-10K-3, was acquired from Ukraine in 2001 and is said to have been studied extensively, with development on the J-15 beginning immediately afterward. While the J-15 appears to be structurally based on the Su-33, the indigenous fighter features Chinese technologies as well as avionics from the J-11B program.
— Wikipedia