Fittingly, the former Leeds Rhinos and England captain entered retirement on a victory as Yorkshire Carnegie won 14-11 at Doncaster Knights on Sunday.
Ultimately, of course, it was not enough to see them through to the Championship play-offs final against Bristol as they lost 44-34 on aggregate over two legs against their Broad Acres rivals.
After leading Rhinos to an historic treble, the legendary Sinfield switched codes last November on an 18-month deal - but announced a fortnight ago he would hang his boots up at the end of this campaign.
So, after the final match of a glorious 20-year career, he was asked if he would instead soon be turning out for his former amateur club Waterhead in Oldham where it all began.
Sinfield said: “No….no! I thought about setting the boots on fire - but not yet.
“It is strange (playing last game) and probably a bit surreal. I still feel like I’ll probably be back in training tomorrow.
“I don’t know but it will probably only sink in in four weeks time when the lads are back in for pre-season training.
“One thing I do know is it’s nice to finish fit and healthy; after 20 years of getting bashed, to come away from the end today and know my body is okay is a huge positive and I’ll now look forward to the rest of my life.
“I’m not too sure what the next step is yet but there’ll be a couple of holidays with the kids, I’ll spend some time at home and then think about what comes next.”
Carnegie had been 13 points adrift after the first leg but Sinfield still felt the squad had the potential to turn things around at a sun-kissed Castle Park.
“We made life tough last week with the score we had to chase but I felt we were capable,” said the 35-year-old, who won seven Super League titles with Rhinos.
“I felt we left points out there today but we got the win. It was important for us to do that but it’s just not enough in the end.
“What a great day to play rugby and a great day to finish as well. It’s disappointing. I felt that we could have bridged the gap today and got the win and got the score we needed.
“I felt we could have pushed Bristol, so it’s disappointing but you have to move on don’t you?”
Sinfield, the fourth highest point scorer in rugby league history, played 18 games for Carnegie, kicking 53 goals, and he is glad he made the jump after more than 500 games with Rhinos. He added: “I’ve just really enjoyed it. There are moments in your life when you get opportunities to do things and you don’t always take them.
“This was something I felt I had to do. I’m really glad I had the courage to step out of something that meant a great deal to me to try something new.
“I never thought I’d get to this stage, here with 40 new mates, and that’s a huge positive to; the friendships I’ve been able to gain on the back of a long rugby league career, to have those friendships now in rugby union, too, has been brilliant. I’d like to thank every single one of the lads. They’ve been fantastic as have the coaching staff who put a lot of effort and work into me.
“To be able to have six really enjoyable months here thrown into a completely new challenge has been great. I know I came across for 18 months but I just felt this was the right time.”
For all Carnegie fell short in their attempt to win promotion this term, Sinfield remains confident they are moving in the right direction.
“They have got a great opportunity,” he added. “The last few years they have been pretty close but with some of the additions in the coaching set-up - (Jersey forwards coach) Steve Boden coming in and obviously Jimmy Lowes - that will add huge value.
“We’ve signed some real quality players as well. Hopefully they’ll get a few more (sunny) days like this next year and the boys can open up and play some good running rugby.
“I’ll certainly be down supporting the team - not every week - but if we get days like this I’m sure I’ll be down watching!
“The nucleus of the team is very, very strong.”