British featherweight Karriss Artingstall made an encouraging start to her Olympic campaign with a comfortable opening victory over Keamogetse Kenosi but Peter McGrail was eliminated in his first round bout.

Macclesfield-born Artingstall, a gunner in the British Army and a bronze medallist at the 2019 World Championships, proved too classy for her Botswanan opponent, who struggled with her headguard on several occasions.

Artingstall was given the nod by all five judges in every round, with four scores of 30-27 and one of 30-26, as she eased into the last-16 of the 57kg category at the Ryogoku Kokugikan in Tokyo.

"It's not my best performance at all, I wouldn't even rate it over a six (out of 10), but I (have) just done what I had to do," said Artingstall after she booked a second round clash against third seed Jucielen Romeu of Brazil.

"Seeds mean nothing to me, it's just a number at the end of the day. I have never come across her myself so I don't know what to expect. But as long as I am in there on my A game, I am a nightmare for anyone to beat.

"I'll warm up throughout the tournament, and you'll definitely see better performances from me."

Kurt Walker overcame a cut to his right eyebrow in the corresponding men's division following a savage left hook in the third round by Spain's Jose Quiles, but the Irishman was awarded a unanimous decision win earlier on Saturday.

"I thought I had done enough. I was dominant in the first and third rounds. In the second he gave his all but then he had nothing left for the third," said Walker. "I had to dig deep, but that's a great first fight for me."

Walker next faces top seed and reigning world champion Mirazizbek Mirzakhalilov of Uzbekistan.

"He's got two arms and two legs like myself so it doesn't bother me," added Walker. "If you want to be the best then you have to beat the best. I'm fighting at the Olympics which is more than I thought I'd be doing last year, so I'm happy."

However, British rival McGrail fell at the first hurdle, the Merseysider dropping a unanimous decision to veteran Thai Chatchai-Decha Butdee, who also competed at London 2012 and Rio 2016.