Hull bantamweight Luke Campbell moved to within one more win of a guaranteed Olympic medal with a nervous 11-9 win over Italy's Jahyn Parrinello at ExCeL.
Campbell started slowly, allowing the Italian to dictate the early stages, although Campbell's success with straight lefts and rights through Parrinello's guard suggested he was a little unfortunate to only tie the first round 3-3.
Although a timely sharp left brought roars from the crowd, Campbell continued to struggle to find his range in the second. But Campbell deserved to shade the round by two points to move into an 8-6 lead, and although he continued to ship occasional right hands from his lively opponent, the 24-year-old edged home to keep his medal hopes on track.
Campbell said: "It's the biggest event on the planet and my first fight in front of the kind of crowd that would make anyone nervous. It was just about keeping calm and now I've got the first one out of the way I'll get better.
"I always tell myself that I won't put pressure on myself and I'll enjoy the occasion, but you can't get away from the pressure - it's there. But I've never worked harder in my life than I have to get to this tournament."
Next up for Campbell is his familiar foe Detelin Dalakliev, whom he will fight for a guaranteed medal on Sunday. Campbell beat Dalakliev to win his European title in 2008 and also knocked him out in the last eight of last year's World Championships.
Meanwhile, London super-heavyweight Anthony Joshua scraped victory in an exciting battle with Cuba's Erislandy Savon to move into the last eight of his weight category and one more win away from a guaranteed medal.
Joshua held on to clinch a 17-16 victory against the 22-year-old Savon, the nephew of the great Felix Savon who won three consecutive Olympic heavyweight medals. Savon looked sharper in the opening exchanges, jolting Joshua with a jab followed by a combination, but a looping right from Joshua stopped the Cuban in his tracks.
Patiently stalking the back-pedalling Cuban, Joshua was dictating the pace of the bout but Savon was a skilful opponent who had success with single counters including a right hand which cut through the host fighter's guard.
Joshua was a bit fortunate to take the first round 6-5, but he had a better start to the second, hurling a big right hook before Savon responded with a couple of rights. Joshua took a two-point advantage into the last, and after he walked onto a big right hand he sensibly chose to hold to see out the final few seconds for a deserved victory.