The midfielder headed home the only goal of the game in the second half as Malky Mackay's men prevailed 1-0, elevating them to 14th in the Premier League standings.
Cardiff enjoyed an energetic start in south Wales before the game descended into a scrappy midfield battle as neither side seized control of the clash.
The breakthrough did come in the second half, however, as Whittingham lost his marker to head beyond Boaz Myhill in the Baggies goal and earn a much-needed victory.
"It was nice to get a goal, especially after last week against Crystal Palace, it was a harsh result on us," he told Sky Sports.
"I thought we bounced back today really well, I thought we dominated for most parts."
Just after the hour had passed, Cardiff winger Craig Noone raced down the right-hand side before curling a precision cross into the box, where Whittingham lost his marker and twisted a fierce header beyond Myhill.
The 29-year-old remained on the floor in the aftermath of the goal but quashed any fears of injury, claiming it was simply fatigue that kept him down.
"I was just too tired to get back up, to be honest," he joked.
"I got hit from the side and then I was facing the other way, I didn't even see it go in to be honest, I just heard the crowd go up."
Whittingham's goal gave the game a thoroughly welcome injection of energy, not necessarily in Cardiff's favour, however, as they were forced to repel a late comeback from the Baggies.
Cardiff survived the onslaught, with the plaudits going to goalkeeper David Marshall who made a superb save - switching directions and diving - to deny Shane Long from point-blank range.
"Marshy made a great save towards the end but apart from that I didn't really think they created too much," Whittingham said.
"I thought we played well, I thought we deserved the win.
"It was a massive win, especially after that Crystal Palace result, we needed to bounce back and we needed three points. We showed great character and it was a great result."
Victory means Cardiff are now four points clear of the relegation zone ahead of their trip to Anfield to take on Liverpool next Saturday.