GLASGOW - Australian cycling star Anna Meares won a fifth Commonwealth Games gold medal Thursday while Bradley Wiggins had to settle for a fourth silver and Glasgow reeled from the withdrawal of athletics legend Mo Farah. On a sweltering opening day to the Games in Scotland, 30-year-old Meares took 0.3 seconds off her own previous 500m time trial best of 33.758 to cross the line at the Sir Chris Hoy Velodrome in 33.435.Compatriot Stephanie Morton claimed silver with a time of 34.079 with England's Jess Varnish winning bronze. Four-time world champion Meares has now won a record-equalling five gold medals in track cycling at the Games, joining compatriot Bradley McGee. It was also a third successive victory in the event for Meares, who has now equalled Kathy Watt's Australia women's cycling record of seven Commonwealth Games medals."I decided to start cycling after watching Kathy at the 1994 Commonwealth Games and now some 20 years later I beat her in most golds. But breaking the record was not my biggest target. I just wanted to be the best," said Meares. Australia also won the men's team pursuit gold in a Games record time of 3min 54.851sec.England, with former Tour de France winner Bradley Wiggins in the line-up, took silver. It was Wiggins' fourth career Commonwealth silver medal. "We've had limited preparations for this and hopefully will look back in two years with gold medals around our necks (at the Rio Olympics) thinking this was the starting point in Glasgow," said Wiggins.World champions New Zealand smashed the Commonwealth record on their way to winning the men's team sprint. England swept the opening triathlon golds with Alistair Brownlee trumping younger brother Jonathan to win the men's title after Jodie Stimpson earlier took gold in the women's event.The two races took place in sweltering conditions, air temperatures peaking at 28 degrees celsius (82F), with the water a balmy 22C, meaning the triathletes didn't even have to wear the ever-cumbersome wetsuits for their swim.Alistair Brownlee, the reigning Olympic champion, made his move halfway through the 10km run after working together with his brother in the opening 1.5km swim and secondary 40km cycle around Strathclyde Loch. Alistair built up a 13-sec lead as the bell went for the final lap of the 10km run, South African Richard Murray holding his nerve to seal bronze at 1:12.Stimpson, a silver medal winner in the World Triathlon Series in 2013, sprinted clear with 400 metres remaining of the final 10km run to win a thrilling women's race. Canada's Kirsten Sweetland claimed silver, with England's Vicky Holland taking bronze in warm, sunny conditions.Action got underway also in the pool where top home hope for a gold medal, Michael Jamieson was upstaged by countryman Ross Murdoch in qualifying for the 200 metres breaststroke final. Murdoch smashed the Commonwealth Games record by over two seconds in a time of 2mins 08.78secs with Jamieson and Calum Tait completing an all-Scottish top three in qualifying.Scotland's Hannah Miley also had the home crowd in raptures in the first heat of the event by breaking her own Commonwealth record in the women's 400m individual medley in a time of 4mins 38.27 secs. Commonwealth Games record times were tumbling all morning at the Tollcross International Swimming Centre as Jamaica's Ali Atkinson went fastest in the women's 50m breaststroke in a Games record time of 30.49secs.The immediacy of the action took some of the sting out of Farah's withdrawal which rocked the Games just as they got underway. The 5,000 and 10,000 metres Olympic champion, 31, was recently laid low by illness and has decided to pull out of the Games in order to work on his fitness ahead of next month's European Championships in Zurich."I really wanted to add the Commonwealth titles to my Olympic and World Championships, but the event is coming a few weeks too soon for me as my body is telling me it's not ready to race yet," said Farah. Kimberley Renicks won hosts Scotland's first gold of the Games when she claimed the women's under-48kg judo title with victory over India's Sushila Likmabam.