Day, who entered the week coming off three straight top-10 finishes, held the clubhouse lead at 5-under for most of the day after taking advantage of easier scoring conditions in the morning at TPC Harding Park.
"... There was definitely a lot of momentum coming in off the previous finishes that I've had, three top 10s, which has been nice," Day said afterward. "The game feels like it's coming around. I'm pleased with it."
Todd later joined Day atop the leaderboard with an impressive outing in the afternoon, with the wind intensifying in the San Fransisco area. His low score comes a few days after blowing a 54-hole lead at last week's WGC-FedEx St. Jude Invitational.
Brooks Koepka, meanwhile, finds himself in a familiar position while searching for his third consecutive PGA Championship title. The 30-year-old posted a 4-under 66 to sit one off the pace.
''... It's only 18 holes right now,'' Koepka said. ''I feel good. I feel confident. I'm excited for the next three days. I think I can definitely play a lot better. Just need to tidy a few things up, and we'll be there come Sunday on the back nine.''
Here's the top of the leaderboard after Day 1:
|Place||Player||To Par||R1 Score|
Even though he shot 68, Bryson DeChambeau may have recorded the most memorable round of the day. The longest hitter on Tour was 4-under at one point, but he stumbled coming in after snapping his driver while leaning on it to pick up a tee.
Second-round action from TPC Harding Park begins at 10 a.m. ET on Friday. Here are the broadcast schedules for the remainder of the week:
In the United States
|Aug. 7||ESPN+ (streaming)||10 a.m. - 4 p.m.|
|Aug. 8||ESPN+ (streaming)||11 a.m. - 1 p.m.|
|Aug. 9||ESPN+ (streaming)||10 a.m. - 12 p.m.|
|Aug. 7||TSN 3 (featured group 1)
TSN 5 (featured group 2)
TSN.ca (featured groups)
|10 a.m.-4 p.m.|
|TSN 3/5||4-10 p.m.|
|Aug. 8||TSN.ca (featured groups)||11 a.m.-4 p.m.|
|TSN 1/4||1-10 p.m.|
|Aug. 9||TSN.ca (featured groups)||10 a.m.-3 p.m.|
|TSN 3||12-9 p.m.|
|TSN 1/4||5-9 p.m.|