A couple of relative unknowns sat atop the leaderboard following the first round of the U.S. Open. Justin Hicks and Kevin Streelman both shot 68 in the opening round, leaving them tied for first place at three-under par after 18 holes.

Tiger Woods made his return from a two-month layoff due to knee surgery and got off to a rocky start with a double bogey on the first hole. Woods had an up-and-down round throughout the first day and finished 18 holes at one-over par after shooting a 72.

Phil Mickelson, who played with Woods in an 'all-star trio' that also included Adam Scott, scored one better then Woods after shooting even-par in the opening round. Woods opened the tournament as the favorite at 2/1 odds at online sportsbook , while Mickelson checked in right behind him at 5/1.

For either former U.S. Open champion to add another major championship to their long list of accomplishments, they will likely have to improve on those scores in the later rounds this weekend.

The favorites that followed Woods and Mickelson on the opening-round odds list mostly struggled at Torrey Pines on Thursday. Sergio Garcia was listed at 16/1 but went into the clubhouse at five-over par, while Padraig Harrington at 20/1 shot seven-over par.

Vijay Singh (28/1) and Stewart Cink (33/1) were both within striking distance after Round 1, as Singh shot even par and Cink finished at one-over par.

Defending champion Angel Cabrera will not repeat as U.S. Open champion after shooting a horrendous 79 on Thursday, which put him at eight-over par. Cabrera is already in danger of missing the cut unless he turns in a miracle round on Friday.

Check out the current U.S. Open odds [1] on golfer matchups and other fun golf future bets.