London - Chelsea have a squad brimming with world-class players but it is the tactical astuteness of manager Jose Mourinho that has given them a clear edge in the Premier League title race.
Mourinho's side opened up a 10-point gap at the top of the table with a 1-0 win over a rejuvenated Manchester United on Saturday built on steely defensive resolve and lethal counter-attacking highlighted by Eden Hazard's goal.
It was a vastly improved United side who arrived in west London on a six-match winning run in the league but they were blunted by Mourinho's tactical nous.
Louis van Gaal's side enjoyed 70 percent possession and had 15 shots to Chelsea's seven but many were speculative long-range efforts and only two were on target.
Mourinho deployed defender Kurt Zouma - rather than the attacking Willian - alongside Nemanja Matic at the heart of his midfield.
The imposing pair nullified the attacking threat of Marouane Fellaini, one of the Premier League's most improved players this season, and the towering Belgian was a peripheral figure throughout.
Wayne Rooney, deployed in midfield, and Ashley Young were well marshalled by Chelsea's watertight defence and Radamel Falcao was physically dominated by John Terry.
"It was difficult, but less than you think," Mourinho told reporters. "Control their direct football to Marouane Fellaini and control the wingers from making crosses on the inside foot.
"When we know Wayne Rooney plays in midfield, we control his progression into the box. Control set-pieces and don't give away direct free-kicks as they have three specialists.
"Wait for a mistake and score a goal. We were able to make their important players disappear. Nobody saw them. They were in our pockets."
Since Mourinho returned to Stamford Bridge in 2013 Chelsea are unbeaten in 11 games against Arsenal, United and Manchester City, taking 23 points from a possible 33.
The 52-year-old, who relishes the relentless and punishing grind of a title race, said last week that people did not like Chelsea because they were boring.
Saturday's clean sheet was their 102nd in 190 matches under him in the Premier League.
While even the most ardent Chelsea fan would concede some sides play a more attractive, attacking brand of football, their relentless march towards a fourth Premier League title is brutally efficient.
"We prepared for it to be like this," Mourinho added. "It was the game we wanted and expected."
Chelsea need eight points from their last six games to win the title for the first time since 2010.