Roberts sinks 20-footer to pip Romero in Senior Open play-off
The 51-year-old Californian holed a 20-foot putt at the first extra hole for par while Romero missed a six-footer.
Roberts, who took a four-shot lead into the final round at the Ayrshire links, survived a near-disastrous back nine when he double-bogeyed 14 and 16 to finish with a round of 75.