In the early days of the race, Kerry, buoyed by his recent marriage to multi-millionaire Theresa Heinz, the heir of the Heinz ketchup fortune, easily out-spent Weld and jumped to the early lead.
However, during the last couple of months, Weld has climbed back into the race and has matched his opponent's fundraising.
The two have planned a series of debates running through the summer and into the fall.
The first, held April 8 at Faneuil Hall, saw sparks fly between the two politicians. Kerry, himself a Yale graduate, jumped on the offensive early and attacked Weld's plan to overhaul the welfare system.
"You spend more time beating up on welfare recipients than you do on finding plans to cover them," Kerry said.
The candidates also sparred over the death penalty, with Weld supporting the measure and Kerry opposing it.
"Kerry voted against the death penalty for cop killers," Weld said.
The two candidates contended again this week and will continue to debate throughout the summer as each vies for the chance to represent Massachusetts in the Senate.
--David L. Greene, Adam M. Kleinbaum, William E. Rehling, Chana R. Schoenberger and Flora Tartakovsky contributed to the reporting of this story.