Overnight co-leaders Karrie Webb and Marina Alex were joined at the top by Jane Park as the weather-delayed first round of the 2015 U.S. Women’s Open concluded Friday morning at Lancaster Country Club.

Park, 28, of Woodstock, Ga., who had five holes remaining when a thunderstorm halted play on Thursday at 6:03 p.m. EDT, polished off a 4-under 66 to join Webb and Alex, both of whom completed their opening round Thursday morning. A 10-year LPGA Tour veteran, Park birdied the par-4 14th hole and registered four consecutive pars.

Play resumed at 6:45 a.m. Friday with 55 golfers needing to complete the first round. The second round began at 7:15 a.m.

Park enjoyed a highly successful amateur career that included berths on two USA Curtis Cup Teams and a victory in the 2004 U.S. Women’s Amateur. Park was also the runner-up in the 2003 U.S. Women’s Amateur and the 2004 U.S. Girls’ Junior. She has not won as a professional. Park also led the Women’s Open through 18 holes in 2006, the last time an amateur has done so.

Park, Webb and Alex own a one-stroke lead over a pair of golfers from the Republic of Korea who figured prominently in the 2012 U.S. Women’s Open at Blackwolf Run in Kohler, Wis.: champion Na Yeon Choi and runner-up Amy Yang. Choi finished up on Friday morning, making a bogey at the par-5 seventh hole but getting the shot back at her last hole, the par-4 ninth.