Hull KR coach Craig Sandercock praised his side for pulling off a "gutsy" win over Wakefield - but an injury to Michael Dobson left the Australian in no mood to celebrate.
Rovers opened their account in the new Stobart Super League campaign thanks to two tries in each half, three of which were converted.
Dobson slotted over the extras when Micky Paea and Con Mika touched down in the opening quarter before being forced off with a shoulder problem.
A lengthy lay-off for the scrum-half would be a major blow for Sandercock, who is already without skipper Ben Galea and stand-off Blake Green.
"It was a courageous and gutsy win and the amount of defence we did on our own line in the second half was unbelievable," he said.
"When you lose your captain and playmaker halfway through the first half, it's always going to be a tough day at the office, but the lads defended their line with pride.
"Michael has a shoulder injury and we will have to have a look at the video because in my opinion some of my boys were taken a little late and that is disappointing.
"Michael will go for scans tomorrow, but it is looking like it could be a period of time. We'll keep our fingers crossed."
The Robins now look set to be without both their starting half-backs for at least the clash with St Helens next weekend.
"It makes it very tough," Sandercock added. "If you take out the first-choice halves from any side it reduces your attacking options. But we didn't give up today and could have used the excuse that we lost our playmakers but we didn't."
Wakefield boss Richard Agar was left to lament his side's failure to make the most of a 10-minute spell when they had a one-man advantage.
Scott Taylor was sent to the sin-bin for holding down former Robin Ben Cockyane, though the Wildcats failed to muster a single point whilst he was off the field.
Referee Robert Hicks' decision to chalk off a first-half Cockayne try for a forward pass by Danny Washbrook also proved costly for the hosts.
"It was a game played in difficult conditions and we knew it would be a game of few chances," Agar said.
"We look at the one that got chalked off. It was a brave call. The linesman let it go, the ref was in-goal and made a brave call, so good on him.
"The boys are dejected and we will look upon the sin-bin period as crucial. I thought that period was vital for us because we got too excited and forced the ball early in the count.
"When they were down to 12 in these conditions, we knew they wouldn't want to be on their try line, but we forced possession and will look at that as one we could have handled a bit smarter."