Airdrie United's six-match unbeaten run came to an end as they were beaten by Lanarkshire rivals Hamilton, who climbed to second in Division One.
The home side made the breakthrough after 25 minutes when Mark McLaughlin headed home Derek Fleming's cross.
Airdrie almost nicked a late equaliser when a Martin Hardie shot was saved at the foot of the post by Dave McEwan.
Hamilton sub Lewis Coult endured a nightmare debut, being booked before going off with a dislocated shoulder.
Hamilton: McEwan, Robertson, Balmer, McLaughlin, Fleming, McArthur, Neil, MacKenzie, McMullan (McJimpsey 84), Carrigan (Coult 61), Torres (Thomson 72).
Subs Not Used: Stevenson, Jellema.
Booked: Coult. Goals: McLaughlin 25.
Airdrie Utd: Robertson, McKenna, McGowan, McManus, Lovering, McDougall (Hardie 62), McKeown, Docherty (Holmes 79), McLaren, Prunty, McPhee.
Subs Not Used: Coyle, Dunn, Hollis.
Ref: M McCurry