His 20 points, to go with veteran Bard Thorn’s try, took them to just a match point behind Toulon with their Pool 3 return showdown in Round 4 set to provide another thunderous encounter.
 
The Leicester win was based on a massive scrum effort from their tight five with Heineken man-of-the-match Williams doing the damage with the boot – including a huge effort at the death – as the 2001 and 2002 champions rose to the formidable challenge provided by the champions with a 25-21 triumph.
 
Matt Giteau was one of Toulon’s high profile players absent through injury, Nicolas Sanchez having the honour of getting matters gets us underway in greasy conditions that produced a couple of mistakes from both sides early on.
 
But there was no mistake from the Leicester pack as they forced the Toulon front row to go skywards at a defensive scrum, Tigers taking the safer option of early points on the board.
 
Up stepped young Welsh No 10 Williams and he looked the coolest player in a red-hot atmosphere as he stroked over the ninth minute penalty goal for first blood.
 
And there was more of much of the same as the Toulon set piece collapsed in an untidy heap as they lost their footing in the testing conditions.
 
Bryan Habana tried to run Toulon out of trouble and former Tigers’ favourite Martin Castrogiovanni was then in trouble for late entry at a ruck that was deemed worthy of leading Welsh referee Nigel Owens reversing his penalty decision.
 
There was no card but there was punishment in the shape of three more points from the boot of Williams – and there was even better to follow for the vociferous Welford Road faithful.
 
A bout of ping pong ended with Drew Mitchell knocking on Matthew Tait’s long kick and that let in veteran 39-year-old All Blacks lock Brad Thorn – a Heineken up winner with Leinster – going over for the opening try.
 
Williams converted for a 13 points advantage at the end of the first quarter, although outside half Sanchez did get Toulon off the mark with a penalty goal.
 
It needed swift – and brave – defensive work by scrum half Ben Youngs to thwart a Toulon attack and Sanchez saw his next penalty attempt shave the left upright to let the Tigers off the hook.
 
Tait then rescued the home side with a try saving tackle in the shadow of his posts but there was no escape from the boot of Sanchez as the Puma landed a second penalty.
 
And Toulon’s comeback was given a bit of assistance, Williams’ attempted long pass kicked up on the bounce by dangerman Habana for the Springbok star to race over unopposed for a try Sanchez converted.
 
Leicester’s unanswered opening 13 points had been answered in identical manner by the visitors as Williams saw two tough penalty chances just drift wide.
 
The Tigers turned up the heat at scrum time – again – with Williams back in the groove with the first points of the second half.
 
But the next Leicester scrum went badly wrong for the home side as the ball squirted out on Toulon’s side and scrum half SebastienTillous-Borde went on the short side and sent Mitchell in for an unconverted try as the defending champions went ahead for the first time after 50 minutes.
 
All Blacks legendary prop Carl Hayman arrived in an attempt to shore up the Toulon front row but the boot of Williams edged Leicester back in front with his fourth penalty success.
 
It was the tactical kicking of scrum half Youngs that put the Tigers in a prime attacking position but the French club’s superb collective defence saved the day – until Williams landed penalty No 5 for a four-point advantage.
 
But Sanchez cut that to a single point with his penalty to set up a real grandstand finish.
 
Try-scoring hero Habana then conceded a penalty inches inside the Tigers half and with the clock showing 79 minutes Williams just had the range to end Toulon’s winning run and seal the win.