Stormy weather turned Saturday\'s third round of the British Open into a test of survival as Darren Clarke and Lucas Glover looked to protect their joint lead. Friday\'s perfect playing conditions were a distant memory as Australia\'s Matthew Millar got things going at Royal St George\'s under glowering, grey skies and a slight drizzle. Playing alone he was seven over through 16 holes The forecast was for much worse to come, especially in the early afternoon which would add extra fangs to a par-70 layout already feared for its length and unpredictability. With the wind picking up by the minute and the rain lashing the first of the 71 remaining Open hopefuls, bogeys were the order of the day as thousands of fans huddled together for shelter under multi-coloured umbrellas . US veteran Tom Watson, who had a hole-in-one at the sixth on Friday, was again a standout as he parred the first six holes and then grabbed a birdie at the par-five seventh. Another long putt to save par at the eighth left him as the only player at that stage under par for the day and at one over for the tournament, still in contention for a record-equalling sixth Open win. Just off the leaderboard and sure to be hauling round the biggest gallery of the day was US Open champion Rory McIlroy who started the day at level par, just four strokes off the lead. The 22-year-old Ulsterman, seeking to become the youngest winner of the Open since 1893, set off with young Amerian Rickie Fowler for the third day in a row and, after pulling off a thick pair of gloves, he clattered his opening drive into heavy rough left of the fairway. He slashed his second into a bunker and failed to get up and down from there as he slipped back to over par territory. McIlroy said he was ready to battle it out with the weather gods. \"I wouldn\'t say I\'m looking forward to it. I\'ve just got to put up with it and persevere,\" he said. Tied for 19th at the halfway stage it will be a different prospect for McIlroy on Saturday as he led after the first two rounds of the year\'s first two Majors, The Masters and the US Open. After two days that accounted for such top names as Luke Donald and Lee Westwood, the two top-ranking players in the world as well as Graeme McDowell, Padraig Harrington and Ian Poulter, the field was uncustomarily bunched up. Related article: Open heartbreak for Westwood and McDowell Popular Ulsterman Clarke, at 42 enjoying a new lease of life, and quiet American Glover, the 2009 US Open champion, were the joint leaders on four under par, but the remaining 69 golfers were all within seven strokes, making it one of the most open weekend fields at the Open ever. The leaderboard was an assortment of old and new with Clarke, 47-year-old Spaniard Miguel Angel Jimenez (three under) and 40-year-old Thomas Bjorn of Denmark (three under) representing the former and 20-year-old English amateur Tom Lewis (one under) and big-hitting American Dustin Johnson (two under) the latter. The only top 10 players in the leading group were world No.3 Martin Kaymer of Germany at three under, and Masters Champion Charl Schwartzel of South Africa at two under. The sentimental favourite though is likely to be the larger-that-life Clarke who had three top 10 finishes in the Open in a five-year spell from 1997, including a tie for second place in 1997 and a tie for third place in 2001.