SPRINGFIELD, N.J. - Lightning followed by steady, heavy rain Saturday forced officials to suspend the third round of play in the 98th PGA Championship at Baltusrol Golf Club. A gloomy forecast for Sunday raised the possibility that the season's final major might have to be extended to a fifth day.

Play was suspended at 2:14 p.m. because of lightning in the area. Of the 86 players who made the 36-hole cut and advanced to Saturday's play, only 37 completed their rounds. Ten contestants, including co-leaders Jimmy Walker and Robert Streb, did not tee off and faced the possibility of going 36 holes Sunday.

Defending champion Jason Day, the world's No. 1-ranked player, and British Open winner Henrik Stenson also did not hit a single shot Saturday.

Sunday's schedule was for players to resume competition at 7 a.m. and for the final round to commence at 8:40 a.m. with the same pairings as round three. Under this plan, with nine-minute intervals between start times, the final twosome would go off around 3:25 p.m.

However, the forecast ranged from a 50 percent to 90 percent chance of thunderstorms in the 12-hour period between 7 a.m. and 7 p.m., raising the distinct possibility of a Monday finish. The rain will be added to what fell Saturday afternoon and what was anticipated to fall in the overnight hours leading into Sunday morning. Many of the greens and bunkers resembled lakes early Saturday evening.

The foul weather Saturday raised questions of why the PGA of America did not elect to start from the first and the 10th tees with three players to a group to ensure a finish that could have headed off the rain, instead of in pairs off the No. 1 tee alone.

Asked whether that was considered, Kerry Haigh, chief championships officers for the PGA of America, replied: "Not significantly.

"It's a major championship and we certainly try, and look at starting from one tee whenever we can," he said.

Haigh said the Friday and Saturday forecasts for thunderstorms were the same and "unfortunately, today they hit us, and [Friday] they missed us."

"I think we have sort of a similar forecast for" Sunday, he said. "Our hope is that those showers or storms hit elsewhere."

Haigh added that Monday is an option to finish "but our primary aim is to try and finish [Sunday] evening."

Of the 37 players who finished the third round, Kevin Kisner, a fifth-year PGA Tour player who won his first tournament this season, fired a 5-under-par 65 and held the clubhouse lead at 5-under 205, 4 strokes off the lead held by Walker and Streb. Former PGA champion Padraig Harrington also shot a 65 and was at 206, with Russell Knox at 207 after a 67.

Harrington was in the 11th pairing on Saturday and Kisner the 15th. Teeing off in the same position on Sunday means they would be starting while the 36-hole leaders were early in their back nine.

Haigh called it "an interesting dynamic for sure, add to the excitement, actually."

Jordan Spieth, who had played just one hole when the horn sounded, speculated that given the weather forecasts, the PGA could even extend into Tuesday.

"So just kind of be as patient as possible," he said. "When we get out, we get out, and just try to take advantage when you can. But there's not going to be the same kind of rhythm and flow."

Streb, who tied a major championship record Friday with a 63 and tied Walker for the lead at 9-under-par 131, called it "kind of a long day trying to figure out what to do."

"Obviously the course looks like it is unplayable," he said. "Everything is under water, regardless of whether the lightning stopped. I guess just go home, hang out with the family, and might be waiting [Sunday] morning, too."