Photo/Illutration Japan's Eri Yamada celebrates their win over Mexico during their softball game at the 2020 Summer Olympics on July 22 in Fukushima Prefecture. (AP Photo)

FUKUSHIMA--Hosts Japan walked off in an extra-innings victory against Mexico on their ace's 39th birthday and the second day of softball at the Tokyo Games, joining the United States at 2-0 in the standings.

Mexico twice tied the game, including in the seventh inning when Japan's ace Yukiko Ueno was three outs away from a complete game and second-straight winning start before a dropped ball by her center fielder let in a run.

Japan reliever Miu Goto managed to escape loaded bases without surrendering a run in the top of the eighth. Her team mate Mana Atsumi drove in Eri Yamada, who started at second base under extra-innings rules, for the 3-2 win in the bottom half.

Goto said wanting to deliver Ueno a birthday win helped in shutting Mexico's rally, and slugger Yamato Fujita described a homer she hit as a present for Ueno.

Elsewhere, U.S. pitcher Monica Abbott dominated from the start to lead her team to a 1-0 victory over Canada.

For seven innings, Canadian batters chased pitches off the plate and failed to make contact on 116 km per hour tosses from one of the game's fastest throwers and a five-time Japanese league most valuable player.

Abbott returned to the same spot on the bench with a toothful grin after her first six dazzling frames. She toweled sweat off her arms, placed a cold pack on the back of her neck and sipped fluids from her pink water bottle. The routine paid off.

Abbott struck out nine in all and gave up one hit. After recording the game's final out, the 1.91-metre (6-foot, 3-inch) left-hander wrapped her arms around catcher Aubree Munro.

"For us to hold down a tough offence and let the defense work, it felt really good," Munro said afterwards.

U.S. center fielder Haylie McCleney scored the lone run after getting on base with a bloop single.

McCleney also threw out pinch runner Joey Lye to prevent her from scoring on a double to right center.

A few minutes of drizzle in the first innings of Japan's game forced players to rush gear under tents. Play was not stopped.

Italy and Australia were scoreless to start the day's final game as scant rain returned.

Canada and Mexico stand at 1-1 in the tournament. Four out of the six teams advance to medal games.