Bard's opposite-field blast cleared the right-field wall with one out in the bottom of the eighth in the game scheduled for seven innings.
"This was my first walk-off home run ever, so it felt good," said Bard. "I was just trying not to do too much up there and I got a good pitch to drive and hit it out. It worked out good for us."
For the struggling Bulls, winding down the season with a 14-33 log, it was certainly a welcome shot in the arm.
"This was a good relief for the team," said winning pitcher Dan Robbins. "We've had a rough season. Not too many things have gone our way, so this helps."
Robbins (2-5), normally the closer, turned in a solid route-going effort in only his second start of the season. The big sidearming righthander out of Lambuth University issued seven hits, struck out five and walked one.
"I've got a good team behind me and I know that all I have to do is throw strikes and they'll make the plays," said Robbins. "I wasn't looking at a number of innings. I was just going to give it my best each inning I was out there."
The Bulls, winners of two of their last three games, picked up their second win in eight meetings with the second-place Union City Greyhounds (27-21).
Sikeston opened the scoring with two runs in the second inning.
Bo Whitaker drew a two-out walk, then moved to second on Shaun Lee's punch single to right field. Tyler Martin then slapped an RBI single to center scoring Whitaker. When the centerfielder bobbled the ball, Lee scampered all the way home for a 2-0 Bulls' lead.
The lead was shortlived, however, as the Greyhounds tallied two runs in the top of the third to even the score at 2.
Following a one-out hit, Robbins' wild throw on a pickoff attempt at first base sent the Union City baserunner to third. A walk and uncontested steal of second put runners at second and third for Joe Melton who lashed a two-run single to centerfield.
"I had one rough inning where I had to figure out what I was doing," said Robbins, "but after that I knew that I could do it. The confidence I've got knowing that I've got good players behind me has made me a better pitcher."
The Bulls retook the lead with a run in the fourth.
Bard, again showing power to the opposite field, lined a leadoff double off the top of the wall in right field.
"I've been working with Coach (Matt) Marshall (Bulls manager) lately and he's really been stressing driving the ball the other way and I've learned how to do that this summer," said Bard, bound for Mississippi Valley State University this fall.
Craig Session, the next batter, then stroked a line shot down the first-base line for another double, sending Bard home.
Bard, tops in nearly every Bulls' offensive category, led the Bulls with a 2-for
-4 day while raising his team-leading average to .342.
He also leads in homers with five, RBIs with 24 and runs scored with 25.
Trailing 3-2, the Greyhounds tied it with a run in the sixth on a leadoff double by Matt Campbell followed by an RBI single from Tyler Owen.
That score stood until Bard's game-winning home run.
The Bulls ruined a strong pitching performance by Union City righthander, Brian Morrell, who also went the distance, allowing five hits with five strikeouts and four walks.
In the nightcap, the Bulls completed the doubleheader sweep with an 8-7 win over Union City to improve to 15-33.
Session got the Bulls off and running with a first-inning grand slam. Sikeston opened the lead to 8-2, then held on for the victory.
Shane Graupman got the win and Tyson Mulvaney earned a save. The Greyhounds fell to 27-22.