The 34-year-old Uttoxeter driver held off world champion Gavin Charlesworth – who was also best man at Shaw's wedding – over 20 laps in Northampton to clinch the title on Sunday.
And the Rebel Racer rated Sunday's victory his best yet.
"I was over the moon," he said. "I've won it twice before in 2002 and 2003, but it was special this time because my family were there."
Shaw started in the second row after a decent run in Friday's qualification race, but still had to reel in Rocester driver Charlesworth, who claimed pole.
Shaw, a father-of-two, said: "I had to give Charlesworth a nudge on the first corner to get past him.
"A couple of others came past me, so I had to overtake them again. But basically from lap five I led all the way with the exception of one lap when the world champion came past."
Shaw is now aiming for a hat-trick of Rebel Racing titles. The speedster is on course for a pole start in October's World Championships and also leads the domestic Rebel Racing standings.
"It can all change though," he said. "It can go wrong very quickly, but at the moment I'm in a good run of form."
Rebel Racing is a contact motor sport that pits driver against driver in equal cars, meaning that success is usually down to a combination of great driving and car preparation.