His 14th-minute volley, in the last game of his emergency loan from Celtic, was enough to see off a determined Dumbarton side.
The hosts created several openings and will wonder how Christian Nade failed to score from close range.
It was not vintage from Hibs, but a potentially important win in the title race as Dundee United could only draw.
Technique alone was not enough to separate Hibs from the home side - and both Martin Boyle and Chris Humphrey found early runs affected by a bobbly surface and Marvin Bartley had to hack a Gary Fleming shot clear from inside the area.
The visitors had to be resourceful and their shrewdest, most assured figure inevitably delivered a telling moment. When Humphrey's cross was headed away inside the area, the ball dropped to Commons and he carefully steered the ball into the bottom corner.
The goal ought to have empowered Hibs, but they were unable to take command of the game.
The home side, instead, proved persistent and Lewis Vaughan briefly rose to prominence.
First, he created a chance for Robert Thomson with good skill, only for Hibs captain David Gray to make a goal-saving tackle, and then drew a good save from Ross Laidlaw with a powerful shot from 25 yards.
Hibs were more assertive after the break, with Boyle making several forays down the left with his quick and direct running. Lewis Stevenson also saw a strike bundled away by Dumbarton goalkeeper Alan Martin, with Humphrey then shooting wide
The home side remained ambitious, though, and some neat skill from Vaughan saw him skip past two Hibs defenders only for Laidlaw to rush out and smother the ball at his feet. Gray then had to head another effort off the line.
On a rare foray upfield by Hibs, an attack ended with Dumbarton defender David Smith clearing off the line. Moments later, Nade should have equalised at the back post, but failed to connect.
Dumbarton manager Steve Aitken: "My team were magnificent. They were up against a strong side, a big club and Neil will get them over the line, but we matched them and for spells were better. On another day, we would have taken more.
"We had chances, Christian's probably came too quickly at him.
"If they can keep giving me that [level of performance], we'll be fine."
Hibernian head coach Neil Lennon: "It was very tough. Dumbarton are on the up, Stevie's going a great job, [and it was] difficult conditions.
"It's a fantastic win and in the end we missed some good chances to put a more flattering scoreline on it.
"Dumbarton put us under pressure for periods of the game and we had to see it out. In the end, we just about deserved to tip over the line."
Match ends, Dumbarton 0, Hibernian 1.
Second Half ends, Dumbarton 0, Hibernian 1.
Corner,  Hibernian. Conceded by Tom Lang.
Attempt missed. Christian Nade (Dumbarton) right footed shot from the right side of the six yard box is close, but misses to the right.
Attempt blocked. Tom Lang (Dumbarton) right footed shot from outside the box is blocked.
Lewis Vaughan (Dumbarton) wins a free kick in the attacking half.
Foul by Marvin Bartley (Hibernian).
Corner,  Hibernian. Conceded by Darren Barr.
Attempt blocked. John McGinn (Hibernian) left footed shot from outside the box is blocked.
Corner,  Hibernian. Conceded by Daniel Harvie.
Substitution, Dumbarton. Tom Lang replaces Stuart Carswell.
Foul by Christian Nade (Dumbarton).
Jordan Forster (Hibernian) wins a free kick in the attacking half.
Attempt missed. John McGinn (Hibernian) left footed shot from outside the box is close, but misses the top right corner from a direct free kick.
Foul by Darren Barr (Dumbarton).
John McGinn (Hibernian) wins a free kick in the defensive half.
Attempt missed. Martin Boyle (Hibernian) left footed shot from the left side of the box misses to the right.
Substitution, Hibernian. Jordan Forster replaces Kris Commons.
Foul by Daniel Harvie (Dumbarton).
Martin Boyle (Hibernian) wins a free kick in the defensive half.
Corner,  Dumbarton. Conceded by Grant Holt.
Corner,  Dumbarton. Conceded by Marvin Bartley.
Attempt blocked. Lewis Vaughan (Dumbarton) right footed shot from long range on the left is blocked.
David Gray (Hibernian) is shown the yellow card for a bad foul.
Andy Stirling (Dumbarton) wins a free kick in the defensive half.
Foul by David Gray (Hibernian).
Foul by Christian Nade (Dumbarton).
Darren McGregor (Hibernian) wins a free kick in the attacking half.
Daniel Harvie (Dumbarton) wins a free kick on the right wing.
Foul by Martin Boyle (Hibernian).
Attempt missed. Mark Docherty (Dumbarton) left footed shot from outside the box misses to the right.
Attempt missed. Grant Holt (Hibernian) header from the centre of the box is too high following a corner.
Corner,  Hibernian. Conceded by Gregor Buchanan.
Substitution, Hibernian. Grant Holt replaces Jason Cummings.
Substitution, Hibernian. John McGinn replaces Chris Humphrey.
Substitution, Dumbarton. Christian Nade replaces Robert Thomson.
Corner,  Dumbarton. Conceded by David Gray.
Marvin Bartley (Hibernian) is shown the yellow card for a bad foul.
Mark Docherty (Dumbarton) wins a free kick in the defensive half.
Foul by Marvin Bartley (Hibernian).
Kris Commons cracked in the only goal as Hibernian stretched their lead in the Championship to six points.