Lott walked out on stage to perform a rendition of 'Angel' with the legendary singer, which they both recorded for his recent album Tuskegee.
Ferguson sang Diana Ross's - and more recently Shania Twain's - part on 'Endless Love' and confirmed that she will duet with Richie once more during his headline show at Liverpool's Echo Arena on November 10.
"Being back on the road is amazing, the crowds have been fantastic and I am very excited about heading back to the UK," Richie said of his current jaunt.
The star will play a further eight arena dates in the UK including shows in Manchester, Sheffield, Newcastle and Glasgow.
Richie will conclude his UK tour at Nottingham's Capital FM Arena on December 15.
The performer's latest album Tuskegee is currently the second-highest selling album in the US in 2012 behind Adele's 21.
Watch the music video for Lionel Richie and Shania Twain's 'Endless Love' below: