Bernhard Langer and Jeff Sluman appeared ready to run away from the field as the third round of the Senior PGA Championship was coming to a close Saturday. That was before they were both undone by a string of bogeys. And then came Jay Haas, who's stunning eagle-2 from the rough on Oak Hill Country Club's No. 17 vaulted him into contention, making this $2 million tournament a compelling three-player race heading into the final round. "Big swings can happen in a heartbeat," said Langer, who was standing alongside Sluman at the 18th tee when the cheers came up behind them for Haas. "That's pretty cool, isn't it really?" Sluman added. As for Haas: "It was a pretty amazing turn of events." When it all shook out, Langer found himself alone on top after an even-par 70 put him at 2-over 212 for the tournament. Haas, who shot a 72, and Sluman, the local favorite who shot 70, were one stroke back. Scott Simpson and Bill Britton were tied at 216 and Greg Norman was part of a four-man group at 217. Otherwise, there's no one else close at an ever-stingy East Course that's surrendered only nine sub-par rounds over the first three days. Then again, anything is possible, because it certainly seemed that way Saturday. "I'm here to make the lowest score I can possibly play, and hopefully that's better than anybody else," said Langer, the Champions Tour money leader, who's after his third win of the year. "But it might not be. Who knows?" Few could have predicted the dramatic change in momentum that occurred over the final half hour of the third round. Playing in the second-to-last group, Langer and Sluman had essentially turned the Senior PGA into a personal match-play event. Sluman got things going when he holed a 55-foot putt for birdie on the par-3 6th, moving him into a tie with Langer at 2 under. The two then proceeded to trade birdies on Nos. 8, 14 and 15 and opened a commanding five-shot lead over the field. Then came an uncharacteristic collapse when both carded bogeys on 16 and 17. Sluman added another bogey on 18, and Langer nearly did so too if not for a clutch 6-foot putt to save par. Haas, in the meantime, was limping through a round in which he was 4 over through 14 holes and five behind the leaders. After a birdie-2 on No. 15, Haas then produced one of the best clutch shots of the tournament after his tee shot at 17 landed in thick rough left of the fairway about 162 yards from the pin. Haas hit a perfect shot that sneaked under an overhanging tree branch, skipped through a narrow opening to the green and rolled directly into the hole, briefly putting him into a tie with Langer and Sluman. "I would like to say that I needed to turn it on or something like that. But I was just hoping to play the last few holes as good as I could," Haas said. "I saw the crowd go nuts up there and then I went pretty nuts." Besides Bruce Vaughan's ace on Saturday, Haas' eagle was only the fourth of the week. "I could probably hit a hundred balls from that same spot and maybe 15 of them get on the green," Haas said. "I mean it was just a freakish thing." Haas, though, gave a shot back when he closed with a bogey. Langer, who posted consecutive 71s over the first two days, has seven top-10 finishes in 10 Champions Tour events. Add to that, the 1993 Masters champion also showed he's capable of being competitive on the PGA Tour after finishing in a tie for 15th at The Players Championship earlier this month. Sluman, who grew up in suburban Rochester, entered the tournament with an objective to simply make the cut after he failed to do so in his two previous times at Oak Hill during the 2003 PGA Championship and the 1989 U.S. Open. Now the 1988 PGA Championship winner is in contention to win on the course which he's played some 500 times. "I'm probably going to be a little nervous, a little jumpy," Sluman said. "Hopefully, I'll just go out and trust what got me here. I've been playing well lately, so there's no reason to think that I won't do that."