The absence of Johnson has been one of the main NRL storylines in the off season, as Warriors fans wondered how the team would cope without the popular half, who contributed 63 tries and more than 120 assists over the last eight seasons.
Keighran has tried to avoid the outside noise and speculation, but admits it hasn't been easy.
"There is a lot of media that I get tagged in - social media and all that," said Keighran. "I try to block it out but obviously I do see it. [But] Shaun Johnson is a step above…there's a highlights reel you probably would have seen so I can't really compare myself to him at all. I can work on my own game, improve from this game."
Keighran had a quiet start to the match, as Blake Green took control of the Warriors attack early on.
"That wasn't the plan but it sort of worked out that way," said Keighran. "He's a good leader, knows how to direct play and that made it real easy for me and I just played off the back of him."
But the former Australian Schoolboys representative gained in confidence as the match developed, best illustrated by his goal kicking.
After missing his first attempt Keighran then managed six-from-six, with the majority tough shots from near the sideline.
"I shanked my first one so I knew I had to correct the second one," said Keighran. "Once that one went over I felt pretty comfortable with the strike. It was good to get that first goal over, and made it easy for the rest of them."
Keighran, who played last year at centre for the Panthers ISP team, also exhibited a handy running game. He beat three defenders with a step, swerve and a dummy to cross in the 29th minute, and made another break in the second half but failed to spot Roger Tuivasa-Sheck on his inside shoulder.
Keighran also showed good awareness to set up Peta Hiku's 69th minute try, as he sprung from dummy half after a quick play the ball from Tohu Harris to ice a memorable debut.
"I was just happy to get out there and play," said Keighran. "But obviously to score and kick a few goals made it that much better so I'm stoked as."
Coach Stephen Kearney was satisfied, without getting carried away, conscious that Keighran enjoyed an armchair ride behind a completely dominant forward pack.
"He was okay," said Kearney. "He did a pretty good job. I've been saying all along that all I expect from him [is]to fulfil his role in the team. He's got some improvement in him but It was a positive start."
Like the rest of his teammates, Keighran also had to contend with a match staged in difficult circumstances, barely 24 hours after the horrific events in Christchurch, where 49 people lost their lives.
"It was quite quiet [in the dressing room], even warm up was a little bit different," said veteran forward Adam Blair. "Everyone realized we do have a job to do, but over the top of that, in the back of our minds, there is obviously a bigger picture that has happened."
