The 35-year-old actor and the 'American Idol' alumni were present at Variety's Annual Power of Women Luncheon.
Clarkson, 35, shared a picture with Priyanka on Twitter where the latter can be seen doing the singer's touch-up before she went onstage to deliver her speech.
"One of my favorite parts of today... My girl @priyankachopra helping me out after sweating my behind off on stage giving a speech... I love her!" wrote the 'Stronger' hitmaker, who was recognised for her contribution to education through XQ Institute.
To this Priyanka replied, "You were amazing @kelly_clarkson you made me laugh cry and inspired everyone in the room! Adore you. Always."
The 'Quantico' star was honoured for her work as the UNICEF ambassador.
Hosted by Judd Apatow, the evening also honoured celebrities such as Octavia Spencer, Michelle Pfeiffer and Patty Jenkins....