A 5-0 Wembley demolition of Bournemouth on Wednesday featured two goals from Son Heung-Min and one each from Christian Eriksen, Harry Kane and Lucas Moura.
The ruthless massacre allowed Tottenham to capitalise on Manchester City's loss at Leicester and move above the champions.
Tottenham began the campaign by setting an unusual record: they became the first Premier League side to fail to sign a single new player in a summer transfer window.
Other off-field problems have beset the north London club, not least delays to the opening of the new 62,000-seat stadium at White Hart Lane which forced them to continue using Wembley as a temporary home for far longer than initially planned.
But despite that Tottenham have continued to prosper on the pitch under Pochettino, who is regarded as Manchester United's preferred choice to become their new permanent manager at the end of the season.
The Bournemouth win followed a 6-2 success at Everton on Sunday, keeping morale high heading into 2019, when Tottenham will also compete in the Champions League knockout stages.
"Over the last six months we haven't complained about anything," Pochettino said.
"The one thing we have kept is the belief and being positive and we have created a bubble.
"We are in this position because we have worked a lot and the players really believe."
Liverpool's win at home to Newcastle means they are now six points clear and favourites to win the Premier League for the first time.
- Title contenders -
Tottenham haven't won the title since the early 1960s and last won a trophy in 2008, but they are firmly in the title hunt.
They didn't resemble contenders when City won 1-0 at Wembley on October 29 to drop Tottenham to fifth, but Pochettino never grew down-hearted.
"We kept our way," Pochettino said. "I wasn't negative eight weeks ago and now I am not so positive. I try to keep a balance of my emotions.
"Of course we are so happy but it hasn't surprised me because we were always focused on us, never on the opponent.
"We are happy because we are in a good position but it doesn't mean too much to be second, third or first now, the most important thing is where you finish.
"Of course now is the challenge to keep the level and try to increase because it is going to be tougher than before. We need to keep humble and work hard."
The scoreline was harsh on Bournemouth, who have now lost four away games in a row.
"It was a really strange game," said manager Eddie Howe, who has been suggested as a potential successor to Pochettino should the latter leave Spurs.
"The game turned on the first goal. We never really recovered from that but all through the match we had opportunities that we didn't take."
The Cherries' afternoon was made worse by a knee injury to defender Simon Francis, who was stretchered off just before half-time
"We are very concerned that it could be serious," Howe said. "It is hugely disappointing for a player who has been magnificent for this club. We hope it is not as bad as it looks."