The 27-year-old runner crossed the finish line after trekking over 26 miles in a time of 2 hours and 19 minutes, just one minute off the record pace. Fred Kieser, 37, of Cleveland, Ohio placed second in 2:22.45.
Toptun took control of the men's race in the first mile and never looked back. He was aiming for a time in the 2:18 range, but the weather produced far from optimal conditions.
It was a chilly start to the marathon. Temperatures at the start of the race were in the lower 20s with wind chills in the mid-teens despite the sunshine.
Organizers estimated that about 18,000 runners started the race. The course route takes runners past such historic sites as Independence Hall, the Betsy Ross House and the Liberty Bell.
For those running or supporting someone in the race, preparation for the cold weather was key.
"I had to run alone and it was cold, so the time is not too bad," Toptun said through an interpreter.
Kieser lost sight of Toptun early on, but said he was satisfied taking second.
"There was no doubt the cold slowed everything down," said Kieser, who coaches a high school girls cross country team in Cleveland. "I thought I might have a chance (at Toptun) at the eight-mile mark, but he just had too much left in the tank."
Ovcharuk waited until the 20-mile mark before making her move.
"I had never run a marathon," Ovcharuk said. "I ran slowly for the first half, then ran faster (from there)."
Dean ran the New York City Marathon just three weeks ago, but she said her time was slowed by an allergic reaction to something she ate. So she wanted to see if she could do better in her hometown.
"I was trying to break 2:40 in New York," said Dean, who does research work at the University of Pennsylvania in Philadelphia. "I had hives and an asthma attack on the course. So I knew Philly was coming up and I love this course. I decided to give it another shot."
Even though there was less wind Sunday than Saturday, any wind that does developed dropped wind chills into the teens. The wind chill measures how much colder it feels against skin with a certain wind at a certain temperature.
The Earthwatch forecast is calling for a warmer day Sunday with temperatures approaching 40 degrees.