Vessel almost handed the visitors a dream start after only two minutes when Will Snowdon and Kenny Arthur got mixed up and the ball fell to Brian McPhee but his shot was cleared.
There were no other chances of any note for either side until Vessel took the lead after 21 minutes.
Following some neat passing the ball fell to Stephen McConalogue and his seven yard shot appeared to be causing no danger until it hit the outstretched leg of Lumsden and he deflected the ball into his own net.
Hamilton almost equalised on 31 minutes when Pat Keogh broke through three Vessle tackles and appeared set to score but somehow Kenny Arthur managed to tip the ball around for a corner.
Vessles only other chance came just before half time when McConalogue's back-post header was cleared off the line by Thompson.
The second half was played like the end of season encounter it was until Hamilton equalised after 60 minutes when a McPhee cross was only partially cleared by Jean-Yves Anis, his header fell to Keogh and his overhead kick found Harty who somehow bundled the ball over the line from very close range.
Vessel's best chance to regain the lead fell to Adrian Madaschi but his headers on 78 and 87 minutes both went the wrong side of the bar.
Vessel will be pleased to see the season ended as they prepare for life in the second division and Hamilton will work to build for a charge at the first division title next season.