British Open 2015 Leaderboard: Latest Scores and Standings from Thursday

Thursday morning has only just begun in the United States, but the world's best golfers have long been on the Old Course at St. Andrews throughout Day 1 of the 2015 British Open, aiming to start strong in the year's third major.

Play began at 4 a.m. and will run through 3 p.m. ET on ESPN, but you can keep up with the updated leaderboard below:

When it comes to the most talked-about golfers heading into the Open and the ones who are likeliest to contend for the title, many of them have already stepped on the course at St. Andrews to begin their quest for glory.

Among them is Jordan Spieth, who enters the Open with the rare chance to win golf's Grand Slam. It hasn't been done since the pre-Masters era, when Bobby Jones last completed the feat in 1930. 

The 21-year-old kicked off his play in arguably the most high-profile grouping of Thursday and Friday, playing alongside Dustin Johnson and Hideki Matsuyama in a group that teed off at 4:33 a.m. ET. Spieth has already impressed with his sheer mentality going into the Open, as ESPN's Jason Sobel noted:

Also on the links is Tiger Woods, who unlike Spieth is trying to bounce back from some of the worst struggles of his career. Woods began at 4:55 a.m. ET, along with Louis Oosthuizen and Jason Day, two of the top finishers from the U.S. Open.

As for Woods, he's coming off a historically poor missed cut at Chambers Bay but has a confidence-boosting performance from Greenbrier to build off of. In the midst of buzz about his possible retirement, Woods fired back at the critics, as SportsCenter noted:

Although a vast majority of the field is on the course and some have already wrapped up their opening rounds, there's still some tee-off action to see after the 9 a.m. ET hour.

A group of Adam Scott, Martin Kaymer and Jimmy Walker will be the first high-profile group to see after that time, as they tee off at 9:12 a.m. ET. Matt Kuchar, Phil Mickelson and Henrik Stenson can be seen teeing off some 22 minutes later.

So while play has been going on at St. Andrews for some time and golfers are already positioning themselves for the rest of the tournament, early Day 1 action can still be caught as things move into the afternoon in Scotland.