Matthew Pennington's first goal for the Club earned Rovers a 1-0 win over Crewe at Prenton Park.
Ronnie Moore made two changes to the team that started at Peterborough with Evan Horwood coming in for the injured Liam Ridehalgh and Jake Cassidy replacing James Rowe.
Cassidy was involved early on, winning possession from Kevin Mellor on the left wing and forcing the defender to concede a free kick, however Koumas' set piece went over the head of Stephen Arthurworrey at the back post.
Cassidy picked up possession midway inside the Crewe half and ran at the visitors' defence on 17 minutes but his shot was blocked on the edge of the area, while a sliced clearance from a Horwood cross hit Matthew Kennedy inside the six yard box but bounced away from goal.
Crewe's first shot came on 23 minutes, with Bradden Inman bringing a fairly comfortable save out of Owain Fon Williams from 15 yards.
Four minutes later Rovers took the lead. Ash Taylor broke from defence and started a move that saw Kennedy win a corner on the left hand side. From the set piece Matthew Pennington rose highest at the back post to power a header into the roof of the net from Koumas' cross.
There was a chance for a second soon after when Pennington combined with Jake Kirby on the right wing but the latter's cut back for Lowe was cleared by Harry Davis.
A long range shot from Cassidy was charged down as Rovers continued to press, while it needed a well timed challenge from Horwood to deny Ajay Leitch-Smith a shot on goal at the other end on 34 minutes,.
The wet and windy conditions were making life difficult for both sides throughout the half but Rovers almost went close again, with Cassidy flicking on a Horwood cross into the path of Lowe but the flag was raised for offside.
Horwood fired over from 25 yards two minutes into the second half while Byron Moore shot across goal and wide from an Inman cross soon after.
The chances went from end to end. Kennedy cut in from the left wing and sent a right foot shot over the bar on 51 minutes and Moore missed again five minutes later from the edge of the area.
Taylor blocked a 20 yard effort from Leitch-Smith on 58 minutes, while Kirby fired over the bar from 18 yards after an excellent move started by Koumas in his own half.
After struggling with a back injury Cassidy was replaced by Stockton on 71 minutes.
The visitors appealed for a penalty on 73 minutes when Matt Tootle went down under a challenge from Pennington but play continued, while substitute Mathias Pogba shot high and wide after another penalty appeal when Leitch-Smith went to ground.
A chipped pass from Steve Jennings gave Lowe a chance, albeit a difficult one, on 76 minutes from which he hit the side netting and Koumas curled past the post from 25 yards five minutes later.
Crewe pushed for an equaliser and had a late corner, but it almost brought a second for Tranmere, with Robinson finding Kennedy with his clearance and the youngster squaring for Stockton who brought a save out of Garratt from 25 yards with virtually the last kick of the game.
Tranmere: Fon Williams, Pennington, Taylor, Arthurworrey, Horwood, Kirby (Robinson 78), Koumas, Jennings, Kennedy, Cassidy (Stockton 71), Lowe. Unused substitutes: Mooney, Holmes, Goodison, Power, Rowe.
Crewe: Garratt, Tootle, Mellor, Davis, Ellis, Leitch-Smith (Ikpeazu 75), Moore (Pogba 67), Inman, Evans, Aneke, Grant. Unused substitutes: Martin, Dugdale, Osman, Guthrie, Waters.
Referee: Scott Mathieson (1st half), Paul Marsden (2nd half)
Yellow cards: Kennedy (36), Evans (37), Mellor (39), Koumas (83)