In a scintillating game, Chelsea came back from behind to beat Leeds 3-1 at Stamford Bridge and continue their good run of form in the league and in Europe.
Leeds scored early through Patrick Bamford, but Chelsea fought back with goals from Olivier Giroud, Kurt Zouma and Christian Pulisic to win all three points at home.
The startling statistic of the game came out later when it was discovered that Chelsea became the first team this season to outrun Leeds, covering six kilometres more than the Whites.
Hasselbaink insisted that is exactly what a team need to do if they are to keep up with Leeds, who he revealed he watched in action regularly in the Championship last term.
He admitted that he did not expect any Premier League side to outwork Leeds this season and feels pleasantly surprised to see Chelsea do so at Stamford Bridge.
The former Chelsea and Leeds striker said on Premier League TV: “Wow, wow. That’s what you need to do to beat them.
“You need to physically match them and go over them.
“I am surprised; I am really surprised.
“I didn’t think a team in the Premier League would be able to do it.
“I have followed them for a long time and I covered their matches in the Championship.
“I know they cover the pitch very well and a lot.
“And for Chelsea to do that has surprised me, but I am happily surprised.”
On Saturday evening against Leeds, Chelsea covered eleven kilometres more ground than they do in their matches on average.
