James wins sprint silver for Wales
Wales' Becky James won silver in the women's sprint as Anna Meares picked up her third title of the Games in another day of Australian cycling dominance.
Megan Dunn sprinted to the women's 10km scratch race title for her second gold as England's Anna Blyth finished third.
Shane Perkins beat Scott Sunderland in an all-Australian sprint final and the Aussies won the men's team pursuit.
New Zealand could not live with Australia's pace, as Northern Ireland won bronze, their first medal in Delhi.
Northern Ireland claim cycling bronze
The Northern Irish quartet of Sean Downey, Martyn Irvine, Philip Lavery and David McCann were too strong for India, catching their hosts less than halfway through their contest to win their first medal on the track since Auckland in 1990.
Welsh teenager James, who won bronze in the women's 500m time trial on Tuesday, upset the formbook to beat Australia's Kaarle McCulloch in their sprint semi-final.
The 18-year-old from Abergavenny led out the first race and held off McCulloch before coming from behind to take the second race on the line and set up a best-of-three final against Meares, who won the 500m time trial and team sprint golds earlier in the week.
But the Australian proved too strong for James, winning the first race with some ease and edging the second by the narrowest of margins.
"This is my third Commonwealths and I have never won the title so to come away with the gold after so long is great, but I had to work so hard for it," Meares told BBC Sport.
"Becky is a beautiful girl and to see her switch and get really aggressive on the track is great to see."
James admitted she was "shocked to get so close" to Meares.
"I was so happy because I knew I was guaranteed a silver medal but to race against Anna was amazing," James told BBC Sport.
"I was really nervous but once I got through the semi-final my nerves went away and I was just excited to be racing against one of the best riders in the world.
"This has been a huge stepping stone for me towards the Olympics and it was such a great experience."
Emily Rosemond of Australia collected the bronze after McCulloch was disqualified in their ride-off for cutting across her team-mate.
Australia have won every men's sprint title at the Commonwealth Games since 1966 and another gold was assured when Perkins and Sunderland won their respective semi-final contests against Sam Webster and Edward Dawkins of New Zealand respectively.
Perkins then had too much for his compatriot, winning the first two of their best-of-three race final while Webster beat Dawkins to take the bronze.
In the women's 10km scratch, Dunn, who won the points race on Wednesday, raced clear of the field in the final lap to win from New Zealand's Joanne Kiesanowski.
Blyth, who had to have her rear wheel replaced early on after suffering a puncture, recovered well to win bronze.
Blythe wins bronze despite puncture