Juan Mata scores twice   London - Agencies Juan Mata scored twice in two minutes to crush Andre Villas-Boas\' hopes of exacting revenge on his former employers Chelsea at White Hart Lane as they won 4-2. The Blues dominated the Tottenham Hotspur team in the first half, taking the lead. Villas-Boas, sacked by Chelsea 226 days ago after eight months in charge, inspired a turnaround in his team\'s fortunes in the second half as Spurs surged ahead through William Gallas and Jermain Defoe. The Blues stunned their former manager with two goals nearly 20 minutes from the end. Mata, signed by Villas-Boas last season, settled the game with two clinical strikes. He scored his fifth of the season and then made it 3-2 soon after with a finish from Hazard\'s pass. Chelsea started strongly and took the lead in the 17th minute when Gallas\' poor header fell straight in to the path of Cahill, who hit a volley beyond Brad Friedel by 12 yards. Peter Cech did well to parry a low Defoe drive but Spurs were poor and both Lennon and Defoe were wasteful in front of goal. Gylfi Sigurdsson offered a brief glimmer of hope when he shot a yard wide - but Chelsea should have doubled their lead moments later when Mata picked up a rebound from his original shot at Friedel, but he skied well over from ten yards.