Harris notched 11 points from his qualifying rides and get through the last chance race-off to make it through to the one-off title decider.
But after a tough night of racing he ran out of steam when it really mattered and trailed in at the back to finish fourth overall with the meeting won by Sheffield’s Adam Ellis.
Harris, who is a three-time British champion, said: “It’s disappointing to miss out at the end, but that’s the way it is.
“It has obviously been a long time since I won it, too long really, so there’s many titles left in me yet because I’m feeling good and the bikes are fast.
“I just wanted to make some starts and come away with that win, but it wasn’t to be.
“At the start of the season we had a few issues with the bikes which were just silly things really, but overall it has been pretty consistent so I have been happy with it.
“Belle Vue is a track I have always enjoyed coming to, but I just didn’t have good results when it was first built. Now I have got some quick machinery underneath me so I’m feeling more confident knowing I can mix it with the best of them.
“Whatever the track was on the night we just had to deal with it and it’s a good, fair track so despite the weather when it started raining it was stiill good.”
Second-placed Panthers are finally back at the Showground on Monday (August 23, 7.30pm) when they face title rivals and current Premiership leaders Wolverhampton in a mouthwatering prospect.
Many experts predict the two sides will finish in the top two of the table and could clash again in the play-off finals in October.
And Harris is backing his side for success over two legs against anybody.
“With our team, if somebody struggles there’s always somebody to step up,” Harris added.
“We’re saving something back for when all six of us click for the Final! I think we’re going to give a hammering to a team, but we all need to click at the same time.”
Panthers are reduced to a six-man team for the rest of the season as Ulrich Ostergaard has confirmed he won’t race again this season.