Flyweight rivals Khalid Yafai and Andrew Selby led the way as Great Britain's boxers took more strides towards qualifying for the London Olympics with five out of five wins in Baku.
Yafai and Selby were joined in the last 16 of their respective weight categories by Thomas Stalker, Fred Evans and Anthony Joshua while there were also four wins out of five for Ireland.
Yafai posted an accomplished performance to beat Japan's Katsuaki Susa 28-16 and said: "I've been out here for a week so it's good to get my first bout out of the way. I accelerated in the later rounds and I'm pretty pleased overall."
European champion Selby, representing Wales, beat Georgia's Severiane Chiladze. However unlike the majority of their team-mates, neither Yafai nor Selby can book their Olympic places with last 16 wins on Tuesday.
With both fighters battling for the single Great Britain berth, even if one fighter were to lose on Tuesday, under AIBA rules he would still have a chance of qualifying if his opponent subsequently went on to reach the final.
For Stalker and Evans, a win on Tuesday will guarantee an Olympic berth. Stalker beat Romaric Bassole of Burkina Faso 13-2 to advance at light-welterweight, while European champion Evans beat Chunsik Kim of Korea 17-8.
Anthony Joshua's big hitting did for Mexico's Juan Hiracheta, with the Mexican's corner throwing in the towel halfway through the first round. Super-heavy Joshua needs to reach the semi-finals to ensure qualification.
Ireland's Roy Sheehan, Joe Ward and Michael Conlon will also box on Tuesday in the knowledge that victory will earn their place at the 2012 Olympics, while super-heavy Con Sheehan also remains in with a shout.
Sheehan beat Croatia's Bora Katalinic 21-17 at welterweight, Ward beat Dilovarsho Abdurakhmanov of Tajikstan 22-4 at light-heavy, Conlon edged to an 18-17 win over Olzhas Sattibayev of Kazakhstan, and Con Sheehan stopped Tajik Faruth Kalonov.
But there was disappointment for Ireland's European light-welterweight champion Ray Moylette, who bowed out in a 19-7 defeat to India's Commonwealth Games champion Manoj Kumars.