The ebay Motors driver collected two podiums, including second place in his final outing of the day, to hold on to fifth spot in the championship, nine points behind fourth placed-man Jason Plato.
The standings are led by Collard’s teammate, Colin Turkington, who won the first two races at Croft.
A delighted Collard said: “Race one was very frustrating as we were quicker than Jason Plato, but I just could not pass him.
“In race two we lost a bit of pace and I was passed late on by Matt Neal, but he failed the ride height test so I picked up the third place trophy.”
He added: “The second place in the final race finished my best day of the season so far. It keeps me in the title race and still in with a chance of a top-three finish.”
Odiham’s Nick Foster had a disaster in his first race at Croft as contact on the first lap saw him forced into the pits.
This meant he started race two from the back of the 30-car grid, but did really well as he fought his way up to 13th.
In his final race he collected another top-10 finish, as he came in seventh.
Foster said: “I made a good start in race one and was looking to stay out of trouble, but then Adam Morgan hit me and broke the suspension and I limped back to the pits.
“My whole weekend was compromised by this, but I felt I had a good day moving up from the back of the grid and taking a top 10 in the final race.”
Collard’s oldest son, Ricky, had another eventful weekend in the Formula Ford Championship, one of the BTCC support races.
In his first race, he qualified an excellent fifth and was the fastest scholarship driver, but all his hard work was undone when the spinning cars of Connor Mills and Connor Jupp tagged him to send him crashing out of the race on lap nine.
The car was still being repaired right up to the start of race two and so Collard was forced to start from the pit lane.
He battled his way through the field to finish ninth overall and then was eighth in his final race, which saw him pick up third place in the scholarship class. He remains second in the standings.
Ginetta Junior driver Jack Rawles, backed by Basingstoke Skip Hire, finished eighth and ninth in his two outings at Croft, having started 11th and 12th on the grid.
The BTCC now takes its summer break, with the next races at Snetterton on Sunday, August 3.
Collard’s youngest son, Jordan, is in action this weekend in the latest round of the British Karting Championship at Larkhill in Scotland.