Goals in the third minute and second minute of time-added-on in the first-half put pay to Albion's defensive approach at Stamford Bridge. Going into the popular Boxing Day fixture Chelsea had only secured two more points on their home turf compared to the Baggies with the Stripes hoping to frustrate Luiz Felipe Scolari's men like so many others had before them.
However, the visitor's defensive plan was undone after only three minutes when Didier Drogba rose above Gianni Zuiverloon at the back post to put the Blues into an early lead. Although faced with an uphill task, Mowbray's men held their own for the rest of the half until, with seconds left until the break, England international withstood a challenge from Paul Robinson and calmly chipped his international colleague to give the host a 2-0 advantage.
"We tried to give ourselves the best opportunity today," Mowbray said.
"I think if we'd have gone two up front too early they could have been out of sight.
"The frustration is the timing of the goals we conceded.
"We did try to frustrate them because, looking at their home results recently, they've struggled against teams that make life difficult for them in midfield.
"Yet to concede such an elementary goal so early on was a blow to us.
"It was a straightforward cross into the box and Drogba beat Gianni, who possesses a great leap, to head it into the net.
"It was very frustrating and yet going in 1-0 down wouldn't have been the end of the world.
"If it had stayed 1-0 for any length of time, the crowd could have got agitated.
"But to concede in first-half stoppage time was very disappointing from our perspective.
"It was also a calamity of a goal."