Even a heavy heart could barely slow Ethiopian distance runner Kenenisa Bekele. But a lapse in concentration cost him.

Less than a month after the death of his fiancee, Bekele finished second in the 3,000 meters at Saturday’s Reebok Boston Indoor Games at the Reggie Lewis Track and Athletic Center. He was leading when he lost track of the lap count and slowed on the final lap, thinking the race was over.

Bekele finished the race with a time of 7 minutes, 41.42 seconds , less than 2 seconds behind Alistair Cragg of Ireland.

“You could see his heart wasn’t in it,” Cragg said. “Ninety-nine times out of 100 he would have beaten me.”

Bekele, the 2004 Olympic gold medallist in the 10,000 metres and silver medalist in the 5,000, had a comfortable lead after 14 laps.

But after sprinting toward the finish line to close out the 14th lap, Bekele slowed down thinking the race was over. Cragg took advantage and ran away with the win.

“I miscalculated, and that was my undoing,” Bakele said through a translator. “It has never happened before.”

It was Bekele’s first competition since Alem Techale’s death. Also a world-class runner who won the 2003 World Youth Championship in the 1,500 metres ,Techale collapsed and died of an apparent heart attack during a training run with Bekele on 4 Jauary. She was 18.

After getting engaged last summer, the two were planning to get married in May. There was a moment of silence in Techale’s honor before the race.

Bekele, widely considered the best long-distance runner in the world, spent several weeks mourning her death and was only able to train one week before Saturday’s competition.

“I knew this race was going to be a difficult one,” he said. “Hopefully by the next race, I think I will be recuperated and do a better job.”

Competing in America for the first time, Bekele was greeted by fans who waved Ethiopian flags and chanted throughout the race.