That was an effort worthy of a U.S. Open champion: Dustin Johnson (-18) produced four birdies in the final five holes to pull clear of the field on a windy Saturday at Crooked Stick Golf Club. Up until that point, the 2010 BMW Championship winner had been treading water at level par for the round.

That spectacular finish makes the 32-year-old the hot favorite to lift the coveted J.K. Wadley Trophy again this year. “The birdie putt on 14 got me going a little bit – especially after I bogeyed 13, which is probably the easiest hole on the course today,” said Johnson.

However, DJ cannot afford to rest on his laurels, despite going into the final round with a three-shot lead over Paul Casey (-15). The Englishman is also in excellent form at the moment and is playing virtually flawless golf. As he did in his second round, Casey remained bogey-free on Saturday.

Roberto Castro (-12), who carded two rounds of seven under par on the opening two days and shared the halfway lead with Johnson, endured a disappointing Saturday. He was unable to find a single birdie, and two bogies ultimately saw him drop to fourth behind J.B. Holmes (-14).

Apart from Casey, the only other player in the leading group to remain bogey-free on Saturday was Adam Scott (-11, T5). Scott’s round of 67 was one of the lowest rounds of the day, matched only by two former FedExCup winners Billy Horschel (-8, T9) and Bill Haas (USA, -4, T26). The Australian climbed into a tie for fifth place with Olympic bronze medalist Matt Kuchar (-11).

It looked for a long time as though defending FedExCup champion Jordan Spieth (-8, T9) would card the lowest round of the day. With two holes remaining, the 23-year-old’s scorecard included four birdies and an eagle. However, two bogies on the final two holes dashed any hope of victory in Indianapolis.

Spieth, who arrived at the penultimate Playoff tournament ranked sixth in the FedExCup, will now struggle to end the tournament in the top five in the season rankings. The top five hold their fate in their own hands at the TOUR Championship: victory in Atlanta would secure these pros the FedExCup title, regardless of other results.

The FedExCup will also add a little extra spice away from the leading group on Sunday. With only 30 of the 70-strong field qualifying for the final tournament of the year, the final day of the BMW Championship is as ruthless as it is exciting.

What promises to be a thrilling final day will be played in groups of two, with the first group due onto the first tee at 8:15.