Porto put themselves in pole position to win the Portuguese Liga title after claiming a dramatic last-minute 2-1 win in Saturday's top-of-the-table showdown with previously unbeaten Benfica.
Long-time pacesetters Benfica came into this weekend's penultimate round of fixtures with a two-point lead over their rivals and knowing that a victory at the Estadio do Dragao would see the club crowned Portuguese champions for the 33rd time.
And Jorge Jesus' men, who face Chelsea in the Europa League final on Wednesday, were on course to claim that win when Rodrigo Lima put them ahead in the 19th minute with a tap-in at the far post.
However, Porto were back on terms within six minutes when Silvestre Varela's left wing-cross took a wicked deflection off Maxi Pereira and beat Benfica goalkeeper Artur at his near post.
Then, with the match a minute into stoppage time, the two-time reigning champions struck what could end up being the title-winning goal when substitute Kelvin lashed home a brilliant left-footed volley from the edge of the box, sending the home fans wild and putting Porto one point clear heading in next week's final round.
Porto still have some work to do though, as they must go to third-placed Pacos de Ferreira in their last game while Benfica are at home to second-bottom Moreirense.
But Moreirense will be no pushovers either as they are battling to avoid the drop and boosted their chances of doing that tonight by beating fellow strugglers Vitoria Setubal 2-1.
Bruninho put Vitoria ahead in the fifth minute but Moreirense hit back with goals from Pablo Olivera (10) and Franco Vinicius (62).
Moreirense were the only side in the bottom five to win today, with last-placed Beira Mar losing 2-1 at Estoril, who battled back from falling behind to a 30th-minute Dani Abalo goal to take the points with efforts from Carneiro Lica (34) and a Rui Rego own goal (87). Beira also had to play the final 22 minutes with a man less following the dismissal of Nildo Petrolina.
Third-bottom Olhanense lost 1-0 at Sporting Lisbon, Diego Capel's winner coming in the 73rd minute, while fourth-bottom Gil Vicente went down 2-1 at Rio Ave.
Alberto Rodriguez (23) and Ahmed Koka (82, pen) netted for Rio Ave with Joao Vilela (66) replying for Gil Vicente, who had Carolino Claudio sent off late on.
Also tonight, Pacos were held 1-1 at Academica, Manuel Jose putting the visitors ahead in the 55th minute but Edinho drawing Academica level with a 72nd-minute penalty.
Despite the draw though, Pacos are now guaranteed a third-placed finish as Braga in fourth suffered a second-half collapse to lose 3-1 to Nacional.
Braga lead through Hugo Viana's 35th-minute effort but Nacional struck three times in four minutes through their three substitutes Ladji Keita (76), Joao Aurelio (79) and Mateus (80) to take the win.
In tonight's other game, Maritimo beat Guimaraes 1-0 through a 26th-minute winner from Danilo Dias.
Information from the Press Association was used in this report