Selby trailed 2-1 but produced a typically gritty performance to win four of the next five frames for a victory that included a break of 100 in the fifth frame.
Akani had chances, but his highest run of 59 in the second frame was never likely to be enough to secure an upset.
China Championship
Selby cleans up to win final frame thriller and punish crucial Higgins error
30/09/2018 AT 16:45
Selby's reward is a meeting Chang Bingyu in the last 64.
Ding Junhui was in top form as he breezed past Daniel Wells with an impressive 5-1 win.
China's leading player lost the first frame to a 51 break before knocks of 89, 125, 79 and 53 completed the win.
He will face Yuan Sijun in the last 64.

China Championship: Results on Tuesday 25 September

Round One
  • Zhao Xintong 5-4 Anthony McGill
  • Zhang Anda 5-3 Marco Fu
  • Martin O'Donnell 5-3 Luca Brecel
  • Liang Wenbo 5-3 John Astley
  • Gary Wilson 5-2 Luo Honghao
  • Mark Williams 5-0 Ken Doherty
  • Shaun Murphy 5-1 Liam Highfield
  • Ding Junhui 5-1 Daniel Wells
  • Mark Selby 5-3 Akani Songsermsawad
  • Barry Hawkins 5-3 Ashley Carty
  • Noppon Saengkham 5-2 Xu Si
  • Graeme Dott 5-4 Stuart Carrington
  • Yan Bingtao 5-4 Chris Wakelin
  • Chang Bingyu 5-3 Robert Milkins
  • Ryan Day 5-1 Mike Dunn
  • Judd Trump 5-0 Rhys Clark
China Championship
Huge tension as crucial frame 17 goes down to nailbiting final black
30/09/2018 AT 15:38
China Championship
Higgins holds slender advantage over Selby in China Championship final
30/09/2018 AT 11:45