Tergat came close to breaking 60mins
The Kenyan looked set for a sub one hour time with three miles to go but was slowed by a headwind to finish in 60mins 30secs.
"It was not easy because it was so windy but I was happy to return that good time," he said afterwards.
"I was well on schedule until that point. Then it became a race between myself and against the clock. I tried my hardest to keep to the schedule.
"The only thing for me was hoping to have a good race. I am running the Chicago marathon on 7 October and that is my target.
"I've always wanted to come back for the event. But with the race always being staged at the end of the track season, it has never been possible."
Susan Chepkemei out-sprinted fellow Kenyan Joyce Chepchumba to win the women's elite race - but paid tribute to her compatriot afterwards.
"We really helped each other all the way through," said Chepkemei.
"I saw she was tired and could feel that she was suffering but I was running well and feeling relaxed.
"It was really hard close to the finish because of the wind but I managed to keep going and I'm very happy with my result.
"I was hoping to beat Paula Radcliffe's record but the early pace wasn't fast enough."
Chempkemei, the fastest woman in the world over the half-marathon distance, hinted that she may return next year.
"This year I've been very happy with my results and my training is going well.
"I owe a lot to my boyfriend, who is also my coach, and to my manager. It was a good race so maybe I shall run here again."
Veteran stage
Britain's best finisher was 40-year-old Paul Evans, who finished fifth.
"I'm enjoying myself now I'm at the veteran stage," said Evans.
"I'm chuffed that I managed to mix it with some of the world's best runners - I finished ahead of some big names."