In his debut season of 2009, he recorded his maiden first-class century, opening the batting against Essex at Lord's in August.
The 21-year-old was recording his second century in three seasons.
At the other end, Kevin Pietersen went on to record his second century of the competition, before being bowled by Jerome Taylor.
In his first season, he made a further thirteen first-class appearances, scoring 370 runs at an average of 17.61, while recording his maiden half century against Leicestershire.
In their second-innings, he recorded his maiden first-class half century with a score of exactly 50, before being dismissed by Tim Linley.
He recorded his first century midway through this season against Lancashire with a score of 150 at the County Ground, Southampton.
In 2004, Hanagan recorded his maiden century of winners, which had been one of his career ambitions when setting out as a young apprentice.
He recorded his second first-class century, 107* again against Gloucestershire, at Worcester in July 1914, when he batted number ten.
He also recorded his first double century that season, which came against Warwickshire.
He did, however, record his second limited-overs century, making 103 against Warwickshire in the Clydesdale Bank 40 at Edgbaston.