GRAND ISLAND,Neb. -  Leading rider Jake Olesiak was at it again Sunday at Fonner Park as he posted a six-win day for the second time this season. Olesiak has dominated the jockey colony this year, and with 10 racing days left in the meeting owns a commanding lead with 55 wins through 21 days of racing. Mike Ziegler is second in the standings with 28 and Olesiak's older brother Jordan has 22 to hold third. On Sunday, Jake Olesiak sat out the first race on the nine-race card then captured four straight with Chablack ($7.20) in the second followed by C C's Jr. ($4.80), C O Sister ($8.20), and Amigos Three ($9.20). He returned in the seventh aboard Toc This Way ($8.20) and closed out the day aboard Flying Mon ($7.20) in the ninth. Olesiak posted his first six-bagger of the season on Feb. 22, the second day of the meet, and has also registered a pair of five-win days, on Feb. 28 and March 8. He appears a lock to capture his third riding title at Fonner Park, where he and brother Jordan have dominated since 2010. Jake also won the riding title here in 2011 and 2013, while Jordan was champion in 2010 and 2012.