The reigning German and European champions moved 13 points clear of nearest domestic rivals Bayer Leverkusen with a 2-1 win at Stuttgart on Wednesday.
However, only late goals from Claudio Pizarro and Thiago Alcantara - the latter's strike coming three minutes into injury-time - prevented Guardiola's men from suffering a shock defeat after Vedad Ibisevic had given Stuttgart a 29th-minute lead.
In addition to acknowledging his team's good fortune, Guardiola urged Bayern, who resume their UEFA Champions League defence with a two-legged tie against Premier League Arsenal next month, to retain full focus.
"We have to stay mentally strong because it's not easy for us when everyone, including the media, says that we are going to be champions, it's all over and the Bundesliga is over," said the Spaniard.
"(The Stuttgart game) has shown again how every game in Germany is a tough one.
"We have to stay calm for the next five to six games in the Bundesliga and especially for the ones in the Champions League."
