Ross Callachan was the hero as Hamilton grabbed their first home Premiership win of the season against 10-man Kilmarnock.
The visitors were reduced to 10 men for over an hour as Clevid Dikamona was shown a straight red card for a reckless challenge on Hamilton midfielder Scott Martin.
Callachan stepped up to ram the spot kick past Danny Rogers for his fourth goal of the season in 72 minutes to ensure the points stayed in South Lanarkshire.
In a week that saw Hamilton awarded three points for St Mirrens Covid breach, it was important that they built on that and a good 1-1 draw with Aberdeen in their last outing.
Killie were down to 10 men midway through the first half when Dikamona was shown a straight red card for a reckless challenge on Scott Martin, when the Accies man wasn't really going anywhere.
Despite that, they probably edged the first half and should have led through Eamonn Brophy, while Accies had flashes at the start and end of the 45, with Callum Smith firing over in the first minute and David Moyo heading wide just before the interval.
Killlie continued to press in the second half but seemed to panic, with Brophy having a couple of chances.
However, Hamilton stepped it up to make their numerical advantage count and finally got there when a Scott McMann shot was handled inside the box and Callachan netted.
Hamilton head coach Brian Rice made just one change to the side that drew with Aberdeen here last time out, with David Moyo in for Marios Ogkmpoe, who was out of the squad.
Kilmarnock boss Alex Dyer made three changes to the side that beat Ross County on November 29, with Dikamona, Alan Power and Greg Kiltie in for Stuart Findlay (suspended), Rory McKenzie and Gary Dicker.
Accies had the first chance of the half inside 60 seconds when Callum Smith was sent through, but lobbed over Danny Rogers and the crossbar.
Scott Martin played a superb ball down the right for Moyo to chase in nine minutes, but Rogers confidently took his driven cross before anybody could take advantage.
Killie should have taken the lead in 15 minutes when Power played a brilliant ball over the top for Eamonn Brophy, but he smashed his shot high and wide when he probably had more time.
The visitors had another decent chance in 23 minutes when Brophy was sent through on the left, but Ben Stirling reacted well to block his shot.
Killie were reduced to 10 men when former Hearts star Dikamona was shown a straight red card for a stupid challenge on Scott Martin, that was certainly reckless to say the least.
The visitors nearly took the lead shortly after that though, when Kirk Broadfoot swung in a free kick from the left and it reached Nicke Kabamba at the back post, but he sliced wide.
Killie also had a strong claim for handball in the box when the ball appeared to strike Lee Hodson's hand, but referee Willie Collum was unmoved.
Hamilton could have opened the scoring on the stroke of half-time when McMann swung in a cross from the left, but Moyo sent his diving header wide of the left post.
Brophy tried his luck again on the hour-mark as he danced his way into the box, but the Hamilton defence were able to clear.
Hamilton should have broken the deadlock in 69 minutes when Nathan Thomas made his way down the right and picked out Scott Martin, but he fired over from just outside the box.
Accies took the lead in 72 minutes when Brandon Haunstrop was penalised for handball and Ross Callachan stepped up to bury the penalty past Rogers.
There were further chances for either side, with Hamilton sub Tunde Owolabi hitting the side-netting after being sent through on the right, and at the other end Power blazed over with a shot from distance.
But Hamilton held out for a very good win.
HAMILTON: Fulton, Hodson (Thomas, 53), Stirling, Easton, McMann, Odoffin, A. Martin, Callachan, S. Martin, C. Smith (Owolabi, 63), Moyo.
Subs (not used): Gourlay (GK), Hamilton, Trafford, Hughes, Mimnaugh, Winter, Munro.
Bookings: McMann (80), Stirling (84), Owolabi (89).
KILMARNOCK: Rogers, McGowan, Broadfoot, Dikamona, Haunstrup, Power, Kiltie (Whitehall, 84), Tshibola, Pinnock, Brophy, Kabamba.
Subs (not used): Doyle (GK), McKenzie, Waters, Mulumbu, Taylor.
Sent off: Dikamona (27).
Bookings: McGowan (63), Hanstrup (72)
Referee: Willie Collum.