By Matthew Abbott Tiger Woods dealt with back spasms during the final few holes of his opening round at The Genesis Invitational. Woods, 48, finished one-over-par 72 at Riviera in his first appearance of the year – and first official PGA Tour start since withdrawing mid-round from The Masters ten months ago. The 15-time major champion finished with five birdies and six bogeys on Thursday. The sixth of those bogeys came with the clubhouse in sight after the Hall of Famer shanked his 176-yard approach on the par-four 18th from the fairway right into the tree line. Remarkably, Woods recovered to …