While buoyed by his result, Winterbottom was smarting that he again fell short of a visit to the podium.
"It was a great way to start our championship campaign with a fourth in Race 1, but so close again to my first podium for the team," he said.
"We started ninth and had pretty good race pace, stayed out of trouble, made some good moves and worked my way forwards into the top five.
"It's a good confidence booster to get a strong top five result in the bag and it's a great feeling knowing we have what it takes to contend this year."
For Pye, it was a disappointing result after a promising third in Friday practice.
After a lacklustre shootout lap, Pye was caught up in the opening lap melee, but was otherwise pleased with his speed.
After the team returned the #20 DEWALT car to the race, Pye was among the quickest cars on track.
"It was a disappointing day for us to start the year, but overall we took away plenty of positives from our speed today," he said.
"We were caught up in an accident on the opening lap which bent my steering, it was frustrating that I was the only car affected by the contact and we pitted in to repair the damage.
"The crew did a mega job to replace the steering arm and get me back on track, and after that it was an absolute jet.
"I'm still really optimistic about tomorrow's chances, we were the second fastest car on track by quite a margin and I'm sure Shane had plenty left in the bag while he was leading, but today I felt we had a really good shot at a podium.
"After everything we went through we finished the race, banked some crucial points and our speed leaves me and the team hopeful for tomorrow and the remainder of the year."
The Repco Supercars Championship field will return to the track for ARMOR ALL Qualifying at 10:05am AEDT on Sunday. Tickets are on sale now.