Earlier this season Arsenal great Henry, who scored 175 Premier League goals for the club, said Sanchez had been Wenger's "best signing in the last six years".
Alexis Sanchez became the first Arsenal player since Thierry Henry to score over 20 goals in his first season and manager Arsene Wenger said the Chilean has exceeded all his expectations.
The effervescent 26-year-old scored a brace in Arsenal's 3-1 Premier League victory against Hull City on Monday to take his tally to 24 goals in all competitions in his debut campaign.
Sanchez has set the Premier League alight since his 35 million pound ($54.78 million) arrival from Barcelona in the close season though his impressive goal tally tells only part of the story of his impact at the Emirates Stadium.
The attacking midfielder has also contributed 11 assists and plays with an unrivalled energy and enthusiasm to inspire an Arsenal team who have claimed 28 points from a possible 30 to all but secure Champions league qualification for an 18th successive season.
His 24 goals, including 16 in the Premier League, have come in all manners from unstoppable long-range thunderbolts to deft finishes at the end of mazy runs.
Arsenal have boasted some of Europe's most gifted attacking midfielders during Wenger's tenure but few combined that with the tenacity and competitiveness of Sanchez who has taken to the physically demanding Premier League like a duck to water.
Earlier this season Arsenal great Henry, who scored 175 Premier League goals for the club, said Sanchez had been Wenger's "best signing in the last six years".
Henry joined the club from Italian giants Juventus in 1999 and scored 26 goals in all competitions in his first season in Arsenal colours and surpassed the 20 goal mark in seven successive seasons.
Wenger, who holds Sanchez in similarly high esteem, has regularly purred over the consistently scintillating performances of his marquee player.
"Yes (he has exceeded all my expectations) because I expected him to be more of a provider than a goalscorer," Wenger told Sky Sports.
"And especially because I play him on the flank where you have less chances. But he has the timing, and the quality of his runs are very good and he gets in good positions to finish."
Should Arsenal beat Manchester City to finish second in the Premier League and retain the FA Cup against Aston Villa later this month the talismanic Sanchez is likely to be pivotal.