The Reds skipper was named in Gareth Southgate’s starting XI for their opening game against the African side in Russia on Monday night.
Henderson has often been criticised for his unadventurous performances in the middle of the park, particularly in an English shirt.
However, the 27-year-old set the tempo for the Three Lions side in the middle of the park with a robust performance.
Harry Kane broke the deadlock from a set piece before the Tottenham striker netted a headed winner on the stroke of full-time to secure three points for England.
However, Republic of Ireland manager O’Nell was quick to praise Henderson for his performance in England’s narrow win over Tunisia.
“He was really, really brilliant. I have a lot of time for him as well because I think his early days at Liverpool, he had a real, real struggle to win the fans over,” O’Neill told ITV Sport.
“He was playing wide right-hand side then they moved him infield.
“It’s taken him a bit of time but I feel his experiences over the last couple of years for Liverpool particularly, playing Champions League football, have given this confidence now.
“I thought he was excellent, got off to a really, really brilliant start. Overall, I thought he was excellent.”
Henderson captained Liverpool FC to the Champions League final last term before the Reds lost 3-1 to 13-time winners Real Madrid in Kiev.
The former Sunderland midfielder was named the Liverpool FC captain after Steven Gerrard left the Anfield outfit back in 2015.
The Reds finished in fourth place in the Premier League table last season to qualify for the Champions League in consecutive campaigns.
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