Edwards kicked five goals and 14 of Dunedin's points when University A was beaten 19-18.
Edwards has scored 96 points this season.
Taieri and Dunedin scraped home in tight games to retain their unbeaten records.
Southern scored five tries when it beat Alhambra-Union 44-38.
Halfback Dean Moeahu played a decisive role to honour his late mother, who died at the weekend, when Green Island gained its first win of the season when it beat Pirates 33-15.
Taieri leads the Speight's Mug competition with 27 points and is followed by Dunedin 25, Southern 24, Alhambra-Union 20, Kaikorai 15, University 11, Zingari-Richmond 8, Harbour 7, Pirates 6, Green Island 5.
Dunedin 19
University A 18
It was fitting flanker Gareth Evans should score the decisive late try to give Dunedin a slender 19-18 win at the University Oval.
He was almost a one-man band as Dunedin struggled to put its game together against a resolute University A that was unlucky to lose.
The students held the upper hand in the first spell and scored three tries to lead 15-6 at the break.
Fullback Matt Faddes used his pace to score the first student try after six minutes and midway through the spell he broke outside the defence and passed inside to pacy wing Sam McLachlan to put University A in front 10-6.
Dunedin messed up its own ball inside its own 22m late in the spell and halfback Nick Annear ran 23m down the short side to score University's third try just before halftime.
Fullback Liam Edwards kept Dunedin in touch with four penalty goals.
When University first five-eighth Stephen Fenemore kicked a penalty goal after 28 minutes it looked all over for Dunedin with the score at 18-12.
The Dunedin forwards camped inside the student 22m for the last 10 minutes but solid defence kept the line intact. The final try came in injury time when Dunedin won a scrum in front of the posts and Evans used his strength to crash over and Edwards converted.
Other players who shone for Dunedin were prop Kelsey Miller, hooker Dan Cairns and flanker Mitchell Zandstra.
Halfback Nick Annear was the pick of the students but he was helped by flanker Sione Teu, lock Anthony Le Douarin and prop Tama Tuirirangi.
Dunedin 19 (Gareth Evans try; Liam Edwards con, 4 pen), University A 18 (Matt Faddes, Sam McLachlan, Nick Annear tries; Stephen Fenemore pen). Halftime: 6-15. Referee: Gareth Reed.
Green Island 33
Pirates 15
Flanker Tala Moli used his strength to score the decisive try to give Green Island its first win of the season at Miller Park.
Green Island had the advantage of the wind in the first spell and led 16-3 at the break.
Pirates used the strong southerly to its advantage to score 12 points in the first 12 minutes of the second spell to close the gap to one point, 16-15.
But the wind died down and Green Island was able to get back into the game.
When Moli scored his try by using his strength down the blindside after sustained forward pressure Green Island led 26-15.
A 70m run by centre Telusa Veainu after an intercept gave Green Island an 18-point win.
The Green Island backline ran with purpose and always looked dangerous with the ball in hand.
Halfback Dean Moeahu was decisive with his passing and the midfield pairing of Veainu and Same Eriepa ran with purpose.
No 8 Junior Sala was able to break the advantage line when he ran from set pieces and fellow loose forward Moli and Mika Mifa did not allow the Pirates backs to break the game line.
Pirates dominated the scrums and No 8 Paul Miller was dangerous when attacking inside the 22m.
Lock Brad Ross dominated the lineout and made 10 clean takes.
Pirates' second-half try came from his lineout take when the forwards drove him to the line and hooker Shaun McCarroll was on hand to score the try. Flanker Garth Swan had a strong game in the loose.
Green Island 33 (Telusa Veainu, Dean Moeahu, Tala Moli tries; Joe Bartlett 3 con, 4 pen), Pirates 15 (Paul Miller, Shaun McCarroll tries; Louis Tili con, pen). Halftime: 16-5. Referee: Mike Smaill.
Kaikorai 25
Harbour 23
It was the Cam Rutherford and Tony Ensor show at a windswept, near-dark Bishopscourt as home side Kaikorai held on in a thriller.
The game came alive with 15 minutes to play and Kaikorai holding an 18-11 lead thanks to Rutherford's six penalties.
Harbour showed good patience and struck back with a try to Hale T-Pole in the corner.
Then, after another good period of attack, the Hawks took the lead when winger George Folau burst over the tryline from a ruck.
With three minutes to play, classy Kaikorai fullback Ensor made a sizzling break, then crossed for the try under the posts a few phases later.
Rutherford completed the simple conversion for a 20-point haul.
Ensor was a constant threat at the back for Kaikorai, while both Rutherford and Matt Te Tana kicked well.
The pack followed the aggressive efforts of Lee Allen and Blair Tweed, with openside flanker Adam Hill in typically industrious form. Harbour backs Lex Kaleca, Loa Iloa and Ollie Cuthill probed with power and precision, with Eben Joubert and T-Pole the stand-outs in the pack.
Kaikorai 25 (Tony Ensor try; Cam Rutherford conversion, 6 pen), Harbour 23 (Johnny Legg, Hale T-Pole, George Folau tries; Ollie Cuthill con, 2 pen). Halftime: Harbour 11-9.
Southern 44
Alhambra-Union 38
Wing Joe Hill and No 8 Simon Knight each bagged a brace of tries as Southern took maximum points with an entertaining win over Alhambra-Union at Bathgate Park.
Southern controlled much of the first hour of the game, at the end of which it led 44-19, but Alhambra-Union finished with a flourish to score 19 unanswered points in the last quarter to gain two bonus points.
Both teams scored five tries but Southern showed more urgency when it mattered to retain the Speight's Challenge Shield.
Harry Uffindell and Hill were particularly strong runners on the wing and first five-eighth Ben Patston controlled play well and kicked 14 points.
Simon Knight, son of former Otago captain Richard, had a powerful game from No 8, and deserved his two tries while props Johnny Mason and Michael Mata'afa anchored a strong scrum.
Captain and hooker Ben Pereira was a lively leader for Alhambra-Union, scoring two tries, while prop Scott Manson and blindside flanker Rory Naylor also impressed.
Halfback Tom Dougherty had a promising all-round game and was rewarded with a try, Peter Breen directed play well and Tui Puloka was a hard runner on the wing.
Southern 44 (Simon Knight, 2, Joe Hill, 2, Harry Uffindell, Johnny Mason tries, Ben Patston 4 con, 2 pen); Alhambra-Union 38 (Ben Pereira 2, Tui Puloka, Matt Daley, Tom Dougherty tries, Peter Breen 2 con, 3 pen). Halftime: 22-14. Referee: Rob Wells.
Taieri 11
Zingari-Richmond 10
Zingari-Richmond came agonisingly close to lifting the silverware and scalping the reigning champion when Taieri escaped with a 11-10 victory in the Downie Stewart Challenge Trophy match at Montecillo yesterday.
In a match in which players had to contend with the ever-changing wind strengths, it was Andrew Reid who secured early points for Taieri through two penalties, before a brilliant breakout by Taieri halfback Nick Roleston led to open side flanker Nathan Young scoring to give Taieri an 11-0 lead at the break.
But a committed Zingari-Richmond side looked to take control in the second half through its forward pack.
Replacement hooker Shota Horie, who displayed his game-breaking capabilities and astute play, scored in the 45th minute to further lift the moral of the pack.
A turnover from a scrum 5m out from its line was typical of Zingari-Richmond's commitment, leading to a break up field and a major all-in altercation at the tackle resulting in Taieri being reduced to 13 men, with two players sin binned as a result.
From a resulting rolling maul, Zingari-Richmond scored through No 8 Chris Bell.
The wind which died as Mark Hunter lined up the conversion, suddenly gusted into life as it went sailing towards the uprights and held the ball up short to deny Zingari-Richmond the victory.
Taieri 11 (Nathan Young try, Andrew Reid 2 pen), Zingari-Richmon 10 (Shota Horie, Chris Bell tries). Halftime: 11-0. Referee: Hamish Davies.
