The Chelsea FC winger scored a late winner in the west London side’s 2-1 win against Liverpool FC at Anfield in the Carabao Cup third round on Wednesday night.
Hazard has now scored six times in eight outings in all competitions in the current campaign to make an impressive start to the season.
The 27-year-old has netted five goals in six games in the Premier League, including his second-ever Chelsea FC hat-trick in a 4-1 victory over Cardiff City.
Chelsea FC managed to see off interest from La Liga giants Real Madrid in the Belgium international in the summer transfer window.
Former Blues legend Townsend believes the Belgian forward needs to be hitting figures in the region of 20 goals a season.
“He needs to add consistency to his goal-scoring,” Townsend told BBC Radio 5 Live.
“He should be a 20-goal a season player. He rarely gets to that mark. He should be up in those numbers.”
Hazard moved to Chelsea FC from Ligue 1 side Lille in the 2012 summer transfer window.
The Blues forward won two Premier League titles, the Europa League, the FA Cup and the League Cup during his spell at the west London side.
Hazard has never won the Champions League during spells at both Lille and Chelsea FC.
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