(CNN) -- Tiger Woods continued his improvement as he completed a two-under-par 70 on Saturday to close to within five shots of PGA Championship leader Matt Kuchar at the halfway stage in Wisconsin.
The world No. 1 was among 78 players who had to finish their second round following fog delays on Thursday and Friday, but flourished as the sun finally shone at Whistling Straits.
After starting with a bogey, the American bounced back with three birdies on the back nine as he followed up his opening 71 to be on three-under 141 in a tie for 22nd.
That put him a shot ahead of world No. 2 Phil Mickelson, who like Kuchar completed his second round -- a 69 -- on Friday.
"I'm not hitting it well here, but I'm putting well and I'm right in the ball game," Woods, who finished 18 over par at the Bridgestone Invitational last weekend, told reporters.
Woods' playing partner Vijay Singh, who won here in 2004, rolled back the years with a superb 66 to move up to equal fifth in a group of 11 players on five under.
The 47-year-old Fijian, himself a former world No. 1 and three-time major champion, carded an eagle and five birdies as he surged up the leaderboard from 57th.
But defending champion Y.E. Yang, the third player in their group, missed the halfway cut after slumping to a 76.
Yang, who became the first Asia-born golfer to win a major when he headed off Woods last year, had a disastrous start to the day with three successive bogeys and then another at 12.
He also dropped a shot at 17 and double-bogeyed his last hole to finish on four-over 148, meaning he missed out along with fellow major winners Louis Oosthuizen (75), Padraig Harrington (71), Lucas Glover (73), Mike Weir (74), Ben Curtis (75), Angel Cabrera (77), Geoff Ogilvy (75) and Trevor Immelman (76).
Harrington, the 2008 PGA champion, had been on course to make it but like Yang he double-bogeyed his final hole to be a shot over the mark of 145 -- and may now need a captain's wild-card pick from Colin Montgomerie to make the European team for October's Ryder Cup.
Montgomerie and U.S. captain Corey Pavin both missed the cut after shooting 83 and 80 respectively to be right at the tail of the field.
Spain's Sergio Garcia also missed out despite an improved 69, which was not enough following his opening 78 which saw him angrily and repeatedly smash his club into the sand after a poor bunker shot.
Kuchar retained his one-shot lead over fellow American Nick Watney, with compatriots Jim Furyk and J.B. Holmes tied for third on 138.
Holmes fired a flawless six-birdie 66 to climb up from 44th, while Furyk carded seven birdies and three bogeys in his 68.
Rory McIlroy (68) and Simon Khan (70) were the leading Europeans in the group on five under, which also included South Korea's 19-year-old Seung Yul Noh (71).
Friday's play was put back by nearly three hours -- the second successive day that fog has delayed proceedings -- meaning organizers are now facing a race against time to get the tournament completed by Sunday.