NO SHIRT REQUIRED: Mahesh Sambasivam heads to the tape at Princeton University’s Weaver Stadium last Sunday on his way to winning the Princeton Healthcare 10k. Pennington resident Sambasivam clocked a time of 33:27 to outlast runner-up ­William Washer of Ogdensburg, N.J., who finished in 33:36. (Photo by Frank Wojciechowski)

For marathoner Mahesh Sambasivam, running against the clock, not his opponents, is his main focus when racing.

When the Pennington resident toed the starting line last Sunday morning at the Princeton Healthcare 10k, he had a number in mind.

“I was shooting for a 34:30,” said Sambasivam, 45, a veteran of several Boston and New York City marathons.

“I usually run my own pace; first place or second place, it doesn’t matter to me. I go by time.”

The wiry Sambasivam outdid himself on Sunday, running a 33:27 to easily achieve his main goal, and in the process, got a bonus as he placed first of 550 finishers in the 34th annual installment of the race,

Sambasivam outlasted runner-up William Washer of Ogdensburg, N.J., who clocked a 33:36 and was in sight of the winner as the runners hit the track at Weaver Stadium for the home stretch of the race. Kathy Rocker of Metuchen was the top female finisher, taking 23rd overall in a time of 40:10.

In reflecting on his win, Sambasivam credited Washer with pushing him to his superb time.

“It was that guy, he set the pace,” said Sambasivam, motioning to Washer across the track. “I let him go until mile five. Getting in the 33:20s, I am ecstatic.”

For Sambasivam, getting into running some 14 years ago has led to moments of ecstasy over the last decade.

“I started running in 1998; my boss at a previous company was a runner,” said Sambasivam, a native of India who works for ConvaTec.

“I have been hooked on it. I always wanted to get involved in sports and this is a way of getting back into it.”

Sambasivam has taken his involvement in the sport to a high level. “When I don’t train for a marathon, it is 50 or 60 miles a week,” said Sambasivam.

“When I am training for a marathon it is 80 a week. I have been at 40 or 50 recently because I have been very busy at work.”

While Sambasivam may be focused on time targets, placing first was a nice payoff for his diligence on the road.

“It is very motivating,” asserted Sambasivam. “The effort I put in pays off. I am a serious runner; I work my butt off.”