Jose Mourinho insisted he and his coaching staff remain the best in the business after his Tottenham tenure took another wrong turn in the 2-1 loss at West Ham.
Mistakes early in each half allowed Michail Antonio and Jesse Lingard to score for David Moyes' side, who are riding high in fourth position.
Lucas Moura pulled one back from a Gareth Bale corner, with Wales star Bale also hitting the crossbar as Spurs failed to claim a share of the spoils.
Tottenham have now lost five of their past six Premier League games, with a 2-0 win against relegation-threatened West Brom the only moment of encouragement during this slump.
Mourinho has never endured such a poor six-game sequence during his decorated career, but he balked at the post-match news conference when it was suggested he might question his own methods.
"No. No, not at all. Not at all. Zero," he replied. "Sometimes the results are a consequence of multiple situations in football.
"Mine and my coaching staff's methods are second to nobody in the world."
Spurs are ninth in the table having been beaten eight times in 24 outings this season. That is the highest number of league defeats Mourinho has suffered since the nine that led to his sacking at Chelsea midway through the 2015-16 campaign.
The West Ham match was his 50th Premier League outing in charge of Tottenham, with those games yielding 23 wins, 12 draws and 15 defeats.
Those 81 points overall are 14 fewer than Mourinho has amassed during his first 50 league games with any other club over the course of his career.
A haul of 95 from 50 at Manchester United is his next worst return, with all of his other posts having yielded in excess of 100 points.
The 15 defeats are more than twice as many as the ex-Porto, Chelsea, Inter and Real Madrid boss has suffered during an initial half-century of matches before now.