The daughter of Shamardal has also won at Kempton and Windsor this season and showed she was still on the upward curve when winning a shade cosily under Graham Lee.
The early pace was strong, allowing Graham to settle Rekdhat on the heels of the leaders.
She travelled well before Graham moved her off the rail to make her challenge with two and a half furlongs to run.
She picked up well to take the lead before holding the late run of Who's That Chick by a length.
Roger said of Sheikh Ahmed's filly: "Rekdhat has improved all summer. Fast ground and a decent gallop are essential for her and when she gets these, she is quite a decent filly."