Michael Dunlop admitted he made an "error" with his bike set-up after finishing third in Saturday's Isle of Man Senior TT.
The Ballymoney rider proved no match for eventual winner Peter Hickman who surged to his fourth win of the meeting with a dominant display in the Superbike class.
Dean Harrison finished second, some 19.9 seconds behind Hickman, with Dunlop a further 20.4 seconds back in third.
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Dunlop said afterwards: "I thought we would have definitely gone quicker. I made an error on my own behalf... I tried something today.
"I thought the pace today would be a lot quicker than it was. But that didn't happen.
"I thought we should have been well into the 136mph (lap times), but for some reason the pace slowed down a wee bit. I don't know why.
"I thought the pace would be a lot quicker and we made a wee change to allow for that. I think we just lost a bit of grip or something.
"The boys were pushing hard, we knew that. It took me a lap or two to get into it.
"We ran out of a bit of scope, really."
Dunlop was always playing catch-up as Harrison and then Hickman set the pace in the Superbike finale.
The 34-year-old made a change to his front suspension at the first pit stop after the second lap, but it failed to ignite Dunlop on the Hawk Racing Honda.
"We struggled and there is only so much you can do with the tools during a pit stop. But that's just the way it was," he said of the early suspension change.
"We always try to go faster and we had to try something."
Dunlop did claim four wins at this year's Isle of Man TT. It leaves him sitting on 25 career victories on the island, just one behind the all-time record of his legendary uncle Joey.
Reflecting on the past week, Dunlop said: "At the end of the day we have won four this week which is pretty good. We could have won more, we could have won less.
"That's just the way the game goes."
Despite breaking the outright lap record on his Superstock on Friday, race winner Hickman opted to ride his Superbike machine in Saturday's Senior TT.
It proved a shrewd move as he controlled the race virtually from start to finish.
"The bike has been a bit of a pig all week, or two weeks. It is hard work when a Superbike does that," he said.
"But the team has done a fantastic job. The Monster BMW Team by FHO Racing, they have worked so hard to find out what was wrong with the bike and how to rectify it.
"And it wasn't fixed until this morning. I went down Bray Hill and kew we had finally cracked it.
"It was a very fast race. Dean (Harrison) obviously got out of the right side of bed this morning, and Michael (Dunlop) has been fantastic for the whole two weeks.
"Just thanks to everyone. The bike was pretty much faultless.
"I think quite a few people thought I was making up excuses last Sunday. But I am an honest person, and if I have a problem it's true and if I haven't, and get beaten fair and square, then fair enough.
"But the bike as bang on and I had a little bit more in the tank if needed. So it was fantastic.
"What an unbelievable race and thanks once again to everyone."
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