The skillful Algerian was the star of the show again with the deciding goal as the Foxes stretched their lead at the top of the Premier League to five points with a 1-0 win over the Hornets at Vicarage Road on Saturday night.
Fans, pundits and football writers alike have been running out of superlatives to describe Mahrez's performances for Claudio Ranieri's side.
Many feel he should be crowned the Player of the Year after notching his 15th goal, with 11 assists also in the bag as the Foxes mount the most unlikely title challenge in the history of English football.
Legendary striker Shearer was crowned PFA Players' Player of the year twice as well as Football Writers Player of the Year and Premier League Player of the Season during a goal-laden career so is well placed to judge what it takes to win such honours.
'He is unbelievable'
And the BBC pundit, who scored 313 goals in 622 career games for club and country, told Match of the Day he feels Mahrez has already done enough.
"He is without doubt, for me, the Player of the Season," Shearer said on MOTD.
"He's been absolutely sensational.
"He didn't get frustrated (at being man marked), he kept wanting the ball and getting on the ball.
"You cannot keep a good man down, who's on the edge of the box, him, a superb touch and even better finish.
"Unbelievable that is, player of the season, 15 goals and 11 assists in the league, just unbelievable in 28 games, superb."
Speculation will intensify if pundit is right
Shearer is loving the Foxes this season and recently predicted they would come out on top in the title race.
Mahrez's form has seen him linked with the likes of Barcelona this season.
And if Shearer's prediction for Player of the Season comes true, that kind of talk will only intensify even if Ranieri's side do win the title in this most open of Premier League seasons.