Chelsea had a couple of decent chances to open the scoring and continued to offer something going forward but found themselves 3-0 down at half-time after strikes from Chris Smalling, Nani and Wayne Rooney.
Fernando Torres pulled one back immediately after the restart, but breaking his long drought did not restore all his old instincts as he unbelievably missed an open goal late in the game.
Rooney also missed a penalty after slipping in an unusually open match between the sides, with Villas-Boas left puzzled by the final score.
"It was a strange game, very,very open and a lot of opportunities for both teams." he told Sky Sports 1.
"If luck could play a better part for our side today, maybe. We had some very good chances to even the score or even to score first.
"The scoreline went crazy in the first half, but we had good opportunities to do something in this game.
"Coming back from 3-0 down is always difficult and we had to take risks without exposing ourselves too much. The second-half recovery was very good and we had a couple of chances to even the score. The scoreline is crazy."
He also brushed aside Torres' horror miss, insisting it was a freak occurrence rather than a symptom of his struggles at Stamford Bridge.
"You have an example of Rooney missing a penalty too, which is basically the same," he said.
"The worst things happen to the best strikers in the world and today it happened to both of them."