Cullen hat-trick wallops Wales in hockey (UK only)
Scotland's Jamie Murray beat Bahamian Rodney Careh 6-2 7-5 to set up a second round clash with England's James Ward in the men's singles tennis in Delhi.
Fourth seed Ward beat Michael Leong of the Solomon Islands 6-1 6-1 on Monday.
The top four women seeds were exempt in round one but fifth seed Heather Watson of Guernsey beat Tara Lambert 6-0 6-0.
In women's hockey, Crista Cullen scored a hat-trick as England beat Wales 4-1 in their first match but Scotland's men lost their first game to Pakistan 3-0.
Leicester full-back Cullen scored from two short corners in the first half before adding her third in similar style shortly after the break.
Charlotte Craddock intercepted a poor pass and rounding the keeper to add the fourth before Sarah Thomas's excellent consolation after a mazy run for Wales.
It was a bad day all round for the Scots as the women lost 2-1 to South Africa.
The men's team in Pool A saw Shakeel Abbasi open the scoring for Pakistan, who finished last at the same venue in the World Cup earlier this year, before Rehann Butt slammed in a second by half-time at a near-empty Major Dhyan Chand stadium.
Behind-the-scenes at Pakistan v Scotland (UK only)
Muhammad Imran made it three to the 2006 Commonwealth silver medallists when he converted the first of the four penalty corners that Pakistan earned.
Scotland face Australia, who have won gold at each of the three Commonwealth Games competitions held, on Wednesday.
Elsewhere in the men's competition, New Zealand crushed Trinidad & Tobago 7-1 in Pool B.
England's women, who won bronze at the 2010 World Cup in Argentina last month and are one of the favourites to win gold in Delhi, next play Canada at 0600 BST on Wednesday.
While pleased with the win, England coach Danny Kerry admitted afterwards that his quest for perfection left him slightly frustrated.
"We utterly dominated for 70 minutes but were poor in the attacking circle," he said.
"If we want to win gold then we have to play better. Having said that, I think it's extremely difficult to be playing in these temperatures.
"We need to set higher standards for ourselves and expect higher standards of our team-mates. If we had done that today it could have been double figures."
Hat-trick scorer Cullen said she was pleased to get off to a winning start and that hard work in training had paid off.
"It's fantastic to get off the mark with a win," said Cullen.
"The girls kept running and running. We made plenty of substitutions because you need to get rest and fluids on board. It's tough on all the teams though."
On her goals, she said, "It's great to get three. Hopefully we can build on it. We know we're a threat from corners but it was nice to show it today."
The result leaves the Welsh, who lost 5-1 to New Zealand on the opening day, facing a must-win match against Malaysia in Pool B on Thursday.
In the archery competition, Paralympic champion Danielle Brown reached the quarter-finals of the women's compound event after beating New Zealand's Amanda McGregor and Scotland's Claudine Jennings.
The Englishwoman is joined in the last eight by team-mate Nicky Hunt, Tracey McGowan of Scotland and Wales's Janette Howells while Chris White of England and Tapeni Kalmaru of Wales reached the men's compound quarter-finals.
In the recurve events, England pair Larry Godfrey and Simon Terry are in the last eight of the men's division with Alison Williamson and Amy Oliver achieving the same feat in the women's competition.
Meanwhile in the badminton, Wales beat Kenya 5-0 and Northern Ireland overcame Sri Lanka 3-2 in the mixed team event, but the Isle of Man lost 3-2 to the Seychelles.
Scotland punished by Pakistan (UK only)