SINGAPORE -- Red Bull's dream of an unbeaten season came to an end at the Singapore Grand Prix, but team principal Christian Horner said he never truly believed it was possible.
The team's winning run, which stretches back to last year's Abu Dhabi Grand Prix, reached 15 races at the Italian Grand Prix, eclipsing the previous record of 11 held by McLaren since 1988.
Horner pointed to a setup issue and Singapore's circuit characteristics for Red Bull's sudden loss of performance, although he did not go into details about the mistakes the team made.
Verstappen, who was also on a record run of 10 victories for a driver, finished the race in fifth place after starting 11th, while Carlos Sainz secured the first non-Red Bull win of the season for Ferrari.
Asked how he felt about felt about missing out on a perfect season, Horner said: "We never expected it. I mean, there were still eight races to go.
"Jesus Christ, you guys have been asking me since pretty much [the second race in] Jeddah. To have got through 15 races is beyond our wildest imaginations.
"For Max to have now 10 in a row is insanity. The last time a driver did that was Sebastian [Vettel] in one of our cars --incredibly proud to have the first and second winningest drivers in Formula One."
Horner also used the opportunity to take a dig at rival team principal Toto Wolff, who said in Monza that Verstappen's record run of ten consecutive wins was "irrelevant".
"While statistics apparently don't matter, they are ones that as a team we're incredibly proud of. We've got this far.
"To have broken the record since 1988 shows just how hard it is to have achieved the kind of supremacy that we've achieved this year, and that's testimony to everybody doing and playing their part."
Asked why Red Bull's performance had dropped off so much in Singapore, Horner added: "It's all engineering stuff. There are no silver bullets in this business.
"I think circuit characteristics are different here and we haven't optimised the car in the right window to extract the most."