He then signed for Middlesbrough in April 1908 who were at that point playing in the top tier of English football, the First Division.
Early in his career as manager Kent would submit his team to the club's board on a Friday before a game, although in later seasons he was able to make the final decision.
However, at the end of the campaign, due to a tight budget, he was made to sell or release several players at the board's insistence.
This was followed by a 14th-place finish in 1912–13, where the club failed to win any of their last 7 home games, and a poor defensive record in 1913–14 meant that Watford were required to beat Q.P.R.
Kent was forced to sell a number of players that summer, but with a side based around a number of local players (including Skilly Williams, Charlie White, and brothers Fred and Val Gregory) he led the club to the Southern League Championship in 1914–15.
Kent managed the side, made-up of mainly local players, in a variety of friendly competitions whilst working in a munitions factory in Essex.
Watford had suffered a financial crisis during the war, but following a fundraising meeting the club was able to resume in Southern League in 1919–20 with much the same side that had won the Championship in 1914–15.
Watford joined the newly formed Football League Division Three in 1920, and Kent led the club to a 6th-placed finish.
Struggling in the 1920–21 season, Kent was allocated the fee from the sale of Frank Hoddinott to sign a player that would drive the club up the league.