Aussie veteran Greg Norman trails leader KJ Choi by one stroke at the halfway point of the 137th Open Championship. Norman rolled back the years with another level-par round to put him second going into Saturday&aposs (UK time) third round. The 50-year-old is chasing his third Open title following victories in 1986 at Turnberry and in 1993 at Royal St George&aposs, and admitted his position was something of a surprise. “My expectations were almost nil coming in, to tell you the truth,” said Norman. “I hadn&apost played a lot of golf. We had a lot of preparation for the wedding (to former tennis player Chris Evert) and the least of my worries was getting out there practising and hitting golf balls.” “The last month my mind has been elsewhere.” “Having said that … you work hard to get yourself into position and I&aposve just got to keep the same mindset going.” Choi sunk a 20-foot putt on the 18th for birdie which gave him the outright lead on one-under, following his 72 on Thursday. The South Korean produced a stunning three-under-par 67 to fire to the top of the leaderboard at the end of day two of the Open Championship. Norman&aposs compatriot Robert Allenby is three strokes off the lead on two-over in a tie for fourth spot while Stuart Appleby is a shot further back on three-over in equal 11th position and Adam Scott (four-over) is in a share of 16th spot with five others. A further stroke behind from Norman was Camilo Villegas, who birdied the last five holes to complete an incredible round of 65 – the best score of the tournament so far – to sit at one-over. Seven players, including Allenby overnight co-leader Rocco Mediate, defending champion Padraig Harrington, American David Duval and last week&aposs Scottish Open winner Graeme McDowell, are two-over. Choi, 38 recovered from a bogey on the first hole at Royal Birkdale to post four birdies – two back-to-back on 17 and 18 – and hailed his round as &aposthe best I&aposve ever played at an Open.&apos “All my shots – the swing, the putting, everything – worked the way I wanted it to,” he said. “I think the key right now is to maintain my body condition and try to finish it out.” “The fans&apos support today was wonderful. I get a lot of motivation out of that.” Much-fancied heavyweights Vijay Singh, Angel Cabrera and Juan Angel Jiminez all missed the cut, while Lee Westwood, Ernie Els and Trevor Immelman scraped through. Despite dropping three shots on Friday to slip down the leaderboard, US Open runner-up Mediate claimed he hit the ball &aposa million times better&apos and was happy with the way he played. “It was good,” he said. “I made two bad swings on 11 and 17 and got what I deserved on those holes.” “I hit a three-wood into the par-four 11th which left me with a chip on but I chipped it sideways a little. And on 17 I hit a bad tee shot, simple.” “Other than that I hit the ball a million times better today but shot four shots more – go figure.” “I couldn&apost do much more. We all want to make a few more putts or hit it better but it&aposs so hard out there.” Meanwhile, Brendan Jones and Craig Parry are both seven-over in a tie for 38th spot while Richard Green (eight-over), Nick O&aposHern (nine-over) and Aaron Baddeley (10-over) have enormous tasks ahead of them if they are to come back into contention. Second Round of the British Open (Par 70): -1: KJ Choi 72 67 E: Greg Norman (Australia) 70 70 +1: Camilo Villegas 76 65 +2: Rocco Mediate 69 73, Graeme McDowell 69 73, Jim Furyk 71 71, Robert Allenby (Australia) 69 73, Alexander Noren 72 70, Padraig Harrington 74 68, David Duval 73 69 +3: Fredrik Jacobson 72 72, Stephen Ames 73 70, Peter Hanson 71 72, Stuart Appleby (Australia) 71 72, Ian Poulter 72 71 +4: Jean Van de Veldt 73 71, Adam Scott (Australia) 70 74, Soren Hansen 75 69, Anthony Wall 71 73, Scott Verplank 77 67, David Horsey 74 70 Also: +7: Craig Parry (Australia) 77 70, Brendan Jones (Australia) 74 73 +8: Richard Green (Australia) 76 72 +9: Michael Campbell (New Zealand) 75 74, Nick O Hern (Australia) 74 75 +10: Aaron Baddely (Australia) 75 75 +11: Andrew Tampion (Australia) 78 73, Geoff Ogilvy (Australia) 77 74 +12: David Smail (New Zealand) 76 76 +14: Rod Pampling (Australia) 77 77 +15: Ewan Porter (Australia) 76 79, Rohan Blizzard, am (Australia) 78 77 +16: Scott Strange (Australia) 84 72 +18: Adam Blyth (Australia) 81 77 +19: Bradley Lamb (Australia) 85 74 +24: Peter Fowler (Australia) 82 82