“I’m very happy with that,” said world number 23 Hatton, who won the Alfred Dunhill Links Championship last year and finished fifth in the Open.
“I got off to a bit of a slow start but holed a couple of putts on the back nine and very happy with the day’s work in the end.”
At 13 under par Hatton held a one-shot lead over Johnson, three-time champion Martin Kaymer, Tommy Fleetwood, Kiradech Aphibarnrat and Pablo Larrazabal, with the top 21 players separated by just four shots on a crowded leaderboard.
