Lambert took a gamble on Sylla when he shelled out £2million to pluck the 22-year-old out of the French Second Division, where he had been impressing for Clermont Foot, and chuck him into the intense heat of a Premier League relegation scrap.
But from the moment Sylla made his debut at Everton in February, he has given every indication of being up to the task demanded of him.
It was the same again on Monday night.
Handed his first start in four games, Sylla did not grab the headlines against Sunderland as Christian Benteke's hat-trick swept the Wearsiders aside.
Yet Lambert noted the energy and drive Sylla brought to Villa's midfield, which ensured their opponents never got a chance to settle and ultimately rocked them so badly Sunderland subsided to a miserable 6-1 defeat which keeps them in relegation bother.
Remarkably, of the eight matches Sylla has been involved in, Villa have won five, drawn two and lost just the one - against Liverpool.
It is a run that threatens to take Lambert's side clear of the drop zone before that potentially do-or-die encounter with Wigan on May 19.
And for that Lambert feels Sylla deserves a lot of credit.
"We needed to try and do something in January," recalled the Scot. "We needed a bit of steel in midfield and managed to get Yacouba.
"He was unknown. But when you bring someone to the club you want them to make an impact and try to do something to help the team.
"Yac has been excellent."
Sylla has managed to make a positive contribution despite not being able to speak the same language as so many of his team-mates, which clearly makes communication difficult.
"He has tried to get a grip of the language, which is important," said Lambert.
"But every time I have asked him to perform he has done it.
"And the thing is, he only a kid. He is still learning, which bodes so well for the future."
The immediate future is a trip to Norwich on Saturday for a game that could shape Villa's season.
Beat another relegation contender and Villa will have clambered to the brink of safety. Lose and they throw the door back open to Wigan to once again manoeuvre themselves into a position where they can make Villa sweat.
To that end, Lambert will hope Ciaran Clark and Karim El Ahmadi recover from the foot and groin injuries that kept them out on Monday night.