Albion won their first competetive game since August after the Baggies secured a 2-0 victory against Exeter City in the FA Cup Third Round.
Salomon Rondon scored after 90 seconds to give Albion an early advantage. Jay Rodriguez fired home from close range as Albion doubled their lead in the first half.
But the gloss was taken off Albion's impressive opening 45 minutes when Hal Robson-Kanu's weak spot kick suddenly gave the hosts some momentum.
Exeter battled back after the break but were unable to find a way past Ben Foster as Albion kept a clean sheet - and recorded Alan Pardew's first win in charge.
"It was important that we won today," said a relived Pardew.
"Some things that we've worked on came to fruition today, especially in the last third. We looked a lot more threatening, could have - and should have - been 3-0 up really. We could have been 4-0 up we had so many chances! But a really professional job.
"The environment wasn't easy," he added. "It was a horrible pitch, no stands down two sides. It would have been easy not to be focused but we were very focused. We got the goal at a good time - first half we were outstanding I thought."