​The first-ever U.S. Junior Amateur semifinal to match two First Coast products was a heavyweight bout that featured punches, counterpunches and no give from either participant.Perhaps Golf Channel commentator Emilia Doran was right when she said, “This was the championship match.”It’s a long way from being over.Miles Russell of Jacksonville Beach has one more opponent and 36 holes to play, with less than 14 hours to recharge for the championship match against Noah Maclauchlan on July 25 at the Saucon Valley Golf and Country Club Old Course in Bethlehem, Pa., beginning at 8 a.m.Russell beat Tyler Mawhinney of Fleming Island 2 and 1 on July 24 after he rolled in a delicate, downhill 12-foot birdie putt at No. 17 and Mawhinney barely missed on the low side for birdie from 10 feet.The two combined for three eagles, 11 birdies and a flurry of memorable shots raining down on the gentle Pennsylvania landscape on a windless midsummer afternoon and evening.Three holes were halved with birdies. Three required eagles to win. Before the two players bogeyed No. 16, they were each 8-under for the day and Russell’s closing putt made him 9-under.”Long day, but a lot of good golf,” Russell told Golf Channel. “You don’t get many of those back-to-back golf days … very few. We take them where we can get them and try to keep that rolling into tomorrow.”Russell said he sees no need to change his game plan of relentlessly hitting fairways and greens, and conjuring short-game magic and clutch putts when he needs them.”Kind of the same game plan,” he said. “Play my game and see how it goes.”Russell will attempt to become the second First Coast native to win the U.S. Junior Amateur. David Duval of Jacksonville won in 1989 at Singing Hills Golf and Country Club in El Cajon, Calif.Miles Russell’s chip-in put him ahead to stayThe pivotal shot was Russell’s pitch-in from heavy rough left of the green for an eagle-two at the short par-4 13th hole to his third and final lead of the day. Russell could have closed the match out at No. 16, but he missed a putt of less than 10 feet for the first time all day, with the ball circling the drain and spinning out of the hole from two paces for his only bogey.They both hit the fairway and green at No. 17 and an official had to rule that Russell was away. His putter face barely touched the ball to send it on its downhill slide to the hole.The championship seems like a mismatch. Russell is seventh on the World Amateur Golf Rankings and Mclauchlan is No. 2,047th. Russell is headed for ACC power Florida State in 2027 and Mclauchlan, from Moseley, Va., is going to Liberty.But it’s match play, where anything can happen and already has for Mclauchlan, whose victims this week include Brayden Jones, who tied Russell for medalist, and Andrew Scortino, the West Junior champion.Russell had a quick start; Mawhinney answeredThe highlights began on the first hole when Russell powered his second shot at the par-5 to within 4 feet, and made the putt fo