EUGENE (AFP) - Britains Mohammed 'Mo Farah smashed the European record in winning the 10,000m at the Prefontaine Classic Diamond League meeting on Friday with a time of 26min 46.57sec. Farah, who is enjoying a strong season after moving to Portland, Oregon, to train with former distance great Alberto Salazar, sliced more than five seconds off the previous European record of 26:52.30, set by Belgian Mohammed Mourhit in 1999. Farah said it was all geared toward the World Championships in South Korea, August 27-September 4. I want a world medal, and it has shown here, said the 28-year-old, who stormed home to finish comfortably in front of Ethiopian Imane Merga. If I keep working hard, Ill be in the mix. Merga clocked a personal best of 26:48.35 and Kenyan Josphat Bett was third in 26:48.99. The race was part of the Distance Night festivities on the eve of the main Prefontaine Classic meeting, which is the fourth stop in the prestigious Diamond League series. Although the crowd was small, it was enthusiastic, and roared as Farah stormed home. I was really happy with the race. I was just sitting back and worked my way through, he said. If it wasnt for the crowd, I could never have done this. With three laps to go, I knew I had a chance for the record. In womens action, world champion Vivian Cheruiyot of Kenya won the 5,000m as injury fears sidelined world record-holder Tirunesh Dibaba. Cheruiyot, who won world gold in Berlin in 2009 triumphed in 14:33.96. She couldnt match the 2011 world-leading time of 14:31.92 she posted in Shanghai last month, but led a Kenyan sweep. Linet Masai, the 2009 10,000m world champion, was second in 14:35.44 and Mercy Cherono third in 14:37.01. Dibaba, the world record-holder and the Olympic gold medallist in both the 5,000m and 10,000m at the Beijing Games, had planned to defend her Prefontaine title, but got bad news from an MRI scan on Friday morning and opted out as a precaution. Officials said the scan found that Dibaba had what doctors called a stress reaction in her right shin. The ailment is a precursor to a possible stress fracture. With the World Championships coming up, the Ethiopian decided to play it safe, officials said. The evening started with Kenyan Moses Mosops unusual world record double. He broke the 30-year-old world marks for both the 25,000m and 30,000m run on the track. Seko clocked 1:13:55.8 for the 25,000m and 1:29:18.8 for the 30,000m. Mosop breaks 30,000m track world record: Kenyas Moses Mosop broke the 30-year-old world record for 30,000 meters run on a track here at the Prefontaine Classic athletics meeting. Mosop, 25, clocked 1hr 26minutes 47.4sec for the rarely contested event. Along the way he broke the record for 25,000 meters run on the track with a time of 1hr 12min 25.4sec. Both previous records had been set by Japans Toshihiko Seko in Christchurch on March 22, 1981. Seko clocked 1:13:55.8 for the 25,000m and 1:29:18.8 for the 30,000m. We started conservatively but by 15 kilometers I felt comfortable, so I pushed the pace, and then really enjoyed the race, Mosop said. The race was part of special Distance Night festivities on the eve of the main Prefontaine meeting, which is the fourth stop in the prestigious Diamond League series. Eight men lined up for the daunting 75-lap contest. Mosop, the 2005 world championships bronze medallist in the 10,000m, had lapped all the other runners with 16 laps to go. The small but enthusiastic crowd, enjoying late summer evening sunshine at Eugenes Hayward Field, gave Mosop plenty of encouragement as he completed his final lap, thrusting his arms skyward after breaking the tape. He admitted that the unusual event had its difficulties. Thirty kilometers on the track is very difficult for concentration, he said, but added the distance on the regular surface was great preparation for marathons on more varied terrain. Speed training, he said.