The 26-year-old Rai, world number 4 in the event, gave ample display of his class by taking the honour in the men's 50 m pistol event as the Indian shooters continued to dominate the ranges.
Read: Jitu, Gurpal make it 1-2 for India in men's 50m pistol shooting
Gurpal Singh also took the spotlight with his silver-winning effort in the same event while Narang, taking part for the first time in the 50m rifle prone event, had to be content with a silver as the shooters did the bulk of the medal shopping during the day.
Writhing in pain, Thakur produced the lift of his lifetime to clinch the bronze in men's 85kg weightlifting, as Indian lifters continued their spectacular show.
Thakur lifted 333kg (150+183) to bag the silver while Richard Patterson of New Zealand won the gold with a total lift of 335kg (151+184). Canada's Pascal Plamondon was third with 333kg (151+182), but Thakur bagged the silver on lesser bodyweight.
Meanwhile, a dominant Indian women's hockey team annihilated hapless Trinidad and Tobago by a whopping 14-0 margin in its third game of the Games.
Read: Indian women annihilate T&T 14-0 in hockey
Star Indian boxer Vijender Singh (75kg) continued his sublime form to enter the quarterfinals along with gritty youngster L Devendro Singh (49kg), but there was heartbreak for Shiva Thapa (56kg), who went down to Olympic bronze-medallist Michael Conlan of Northern Ireland. Manoj Jhangra, too, made the quarterfinals with a convincing win.
Read: Boxers Vijender, Devendro, Jangra reach CWG quarters
Vijender, a former Olympic and World Championships bronze-medallist, outpunched Namibia's Mujandjae Kasuto 3-0 in a lopsided contest to make the last-eight stage.
Such was the former world number one's domination that he managed a perfect 10 score from every judge in each of the three rounds.
Devendro Laishram (L) celebrates after defeating Sri Lanka's Madushan Gamage in the men's light flyweight preliminaries round bout at the Commonwealth Games 2014 in Glasgow, Scotland. (AP Photo)
With the addition of four more medals, India's overall haul swelled to 25 with seven gold, 12 silver and seven bronze and were placed fourth in the standings.
Australia were at the top with followed by England and hosts Scotland.
Rai shot 194.1 to bag his first Commonwealth Games gold on debut while Gurpal had an aggregate of 187.2 to win the silver, his first international medal. Australia's Daniel Repacholi was third.
With three medals in shooting, India's tally from the Barry Buddon Center has shot up to 12 (4, 7, 1), three more than England who have eight, including three gold medals.
Nepal-born Rai, who won a gold (in 10m air pistol) and a silver (in 50m pistol) in the World Cup last month, was third in the first series but then recovered quickly and led the field throughout after that.
In weightlifting, Thakur was trailing at third with a lift of 150kg after completion of snatch though the gap with the leaders - Patterson and Plamondon - was just one kilogram.
The Indian began with 142kg and then went onto lift 147kg and 150kg in his next two attempts. Patterson, the favourite and last year's Commonwealth Championships winner, began with 147kg and lifted 151kg in his second attempt. He went for 154kg in his third attempt but failed to lift it.
The 20-year-old Thakur had finished second in the Commonwealth Championships. In clean and jerk, Thakur went for 179kg in his first attempt, but could not lift it. But he was successful in his second attempt to jump to the top spot.
Plamondon then lifted 182kg to take the top spot.
Thakur was non-plussed and he came out to lift 182kg to total 333kg and equal Plamondon.
Hammer thrower Narayan Singh Chandrodaya was the only Indian to qualify for the final round in a disappointing outing for the Indians on the second day of athletics meet.
Chandrodaya finished fifth with 67.95m in qualification group A and his effort was good enough to make it to the final rounds of hammer throw competition at Hampden Park. The other Indian in the fray, Kamalpreet Singh finished sixth in qualification round B to miss out on finals.
Chandrodaya Narayan Singh competes in the qualifying round of the men's hammer throw athletics event at Hampden Park during the 2014 Commonwealth Games in Glasgow, Scotland. (AFP Photo)
Shot putter Om Prakash Karhana finished sixth in the final round. In women's 400m race, M R Poovamma failed to advance to the final round after finishing fifth in semifinals number one with an effort of 52.88secs. She finished 14th.
Shradha Narayana also failed to advance to the finals after finishing sixth in the semifinal number one with a timing of 11.71secs. In men's para-sport discus throw F42/44 finals, Jai Deep finished fourth with a best throw of 38.68m.
There was disappointment in women's 50-metre rifle prone event as Meena Kumari and Lajja Gauswami finished sixth and 11th, respectively, in the finals.
India drew a blank in the badminton mixed team event after going down fighting to Singapore 2-3 in the bronze medal play-off.
Despite star attraction Saina Nehwal's pull out from the Games in the last minute, there were high expectations from Indian shuttlers especially with P V Sindhu, Parupalli Kashyap and reigning Commonwealth women's doubles champion pair of Jwala Gutta and Ashwini Ponappa up their ranks.
But the team failed to deliver when it mattered most to return empty handed from the mixed team event.
Read: Indian shuttlers bite dust in mixed team event
It was not the best of starts to the bronze medal encounter for 10th ranked India, who lost to 2010 Delhi Games bronze medallist England 0-3 in the semifinals on Sunday.
Indian men's table tennis team failed to secure a medal for the first time at the Games after being stunned 1-3 by Nigeria in the bronze medal play-off at the Scotstoun Sports Campus.
The unexpected loss meant Indian men will return empty handed from the team event for the first time since the sport's introduction in the Games at Manchester in 2002.
India's wait for its first squash medal at the Commonwealth Games was prolonged with Saurav Ghosal's fighting loss to Englishman Peter Barker in the bronze medal playoff.
World No 16 Ghosal needed to come up with something special for his first win over his eighth-ranked opponent. The Indian tried his best before going down 5-11 11-6 5-11 6-11.
India's leading female player Dipika Pallikal had suffered a quarterfinal loss against England's Alison Waters and Joshana Chinappa bowed out of the competition in the round of 16.
Narang, who has won four medals each in both the 2006 and 2010 Commonwealth Games but in other events, lost out the gold to Warren Potent of Australia by 0.7 points.
Narang collected 203.6 in the 20-shot final round, while gold-winner Potent scored 204.3. Kenneth Parr of England bagged the bronze.
This is Narang's first Commonwealth Games medal in his first appearance in 50m rifle prone, which is not his pet event. Narang, who won a bronze in men's 10m Air Rifle in 2012 London Olympics, will also take part in men's 50m rifle 3 position event on Tuesday.