The 27-year-old shares third place with Italy's Costantino Rocca and South Africa's Richard Kaplan. The trio are two shots behind Frank Nobilo of New Zealand.
Straub, 30, owes his seven-under-par second round of 64 to a change of putter. The American ditched his faithful putter of 17 years before the tournament and duly sank five birdies and an eagle as he moved to a 10- under 132 for the tournament.
"I'd had the old putter since I was 13 and this is the first tournament I've played since I stopped using it. I putted real well today," said Straub, who is looking for his first tournament victory.
Another Englishman, Mark Davis, had set the new mark for the slightly altered Hong Kong Golf Club course earlier in the day with a 64.
Britain's Laura Davies and the American John Daly are among five pairs sharing third place after the first round of the US PGA-LPGA Penney Classic in Florida.
Under a best-ball format at the event, they compiled a seven-under-par 64 to lie two shots off the American leaders, Barb Mucha and Mike Brisky.
They began to play well on the back nine and closed with birdies on the eighth and ninth holes to go one stroke ahead of Dottie Pepper and Jeff Sluman.Reuse content