Calderwood has just returned to action after a broken ankle
Wigan (4) 18
Tries: Colbon 2, Calderwood
Goals: Richards 3
Hull KR (0) 12
Tries: Walker, Newton
Goals: Cooke 2
Winger Mark Calderwood's try with just four minutes remaining clinched a hard-fought victory for Wigan.
The Warriors, thrashed 46-10 by fierce rivals St Helens on Good Friday, had taken a 10-0 lead just after the break thanks to two tries from Liam Colbon.
Two quick-fire efforts from Chev Walker and Clint Newton, plus two Paul Cooke goals, then put Rovers 12-10 in front.
But a Pat Richards penalty levelled it before Calderwood's late score ensured the points went to the visitors.
Wigan coach Brian Noble
"I thought we were worth our win and, had we executed a little bit better, we could have scored a few more points.
"But Hull KR were never going to go away, and were always looking for that reason to stay in the game.
"In relation to what we dished up last week, when we didn't look enthusiastic at all, to defend your line for 23 plays was a great testament to the effort."
Hull KR coach Justin Morgan
"You can't ask players to be doing this for much longer. The game has come a long way, and it takes so much out of your team and out of your players.
"We were a bit fatigued and a bit tired after Friday but I think in all our games this year we've been competitive, especially two games over Easter against two established teams in Hull and Wigan.
"To win one and be very competitive in the other shows we've come a long way, but it'll be the aftermath of this weekend and how we put the pieces back together, which will be the test for us."
Wigan: Richards, Calderwood, Goulding, Carmont, Colbon, Barrett, Leuluai, Fielden, McIlorum, Coley, Bailey, Hansen, O'Loughlin.
Replacements: Higham, Paleaaesina, J. Tomkins, O'Carroll.
Hull KR: Briscoe, Steel, Walker, J. Webster, Fitzhenry, Galea, J. Webster, Vella, Cockayne, Mills, Gene, Newton, Murrell.
Replacements: Aizue, Lovegrove, Cooke, Fisher.
Referee: B Thaler (Wakefield)