An extra time winner by Alessandro Matri kept Juventus on track for the treble after the Italian champions ended a 20-year wait for Cup final victory with a 2-1 win over Lazio on Wednesday.

Juventus were stunned after just four minutes when Stefan Radu rose to beat Marco Storari with a powerful header from a free kick after Paul Pogba had given away a needless foul on the right flank.

Juve got back on level terms thanks to Giorgio Chiellini's half-volley in the 10th minute.

After the match finished all square after 90 minutes, Matri, back on loan at Juve after being sold to Milan in 2013, made the difference when he latched on to Carlos Tevez's lay-off inside the area to bundle past Etrit Berisha in the Lazio net.

Juve held on to their lead amid a tense second period of extra-time to send the black and white half of the Stadio Olimpico into raptures as the champions secured their first double since 1995.

Juve coach Massimiliano Allegri was without Claudio Marchisio and Alvaro Morata, the Spanish striker whose late leveller in a 1-1 draw away to Real Madrid secured Juve's Champions League final against Barcelona in Berlin on June 6.

Allegri was also without number one goalkeeper Gianluigi Buffon, and the big Italy keeper's absence was felt almost immediately when Storari struggled to reach Radu's powerful header from a free kick on the right.

Yet Juventus, who beat Lazio 3-0 and 2-0 in their Serie A encounters this season, were soon back on level terms.

The fingers of blame had pointed at Chiellini after Radu's opener, but the big Juve defender was in the right place at the right time when Andrea Pirlo fired in a free kick from 25 metres out on 10 minutes.

Pirlo's curling delivery was headed into the area by Pogba and Chiellini was left enough space to connect and beat Berisha with a close range volley.

If the early goals provided some early match drama, they did not spark a Cup goals fest before the interval.

Fernando Llorente fired a header just over Berisha's bar and after Pirlo saw a free kick blocked, what followed displayed Lazio's threat on the counter.

Brazilian Felipe Anderson carried the ball all the way through the Juve midfield to offload for Danilo Cataldi, forcing Buffon to collect down low to collect.

Lazio threatened again on the half hour, when Storari had to be at full stretch to cover a half-volley from Marco Parolo, while at the other end Tevez was unlucky when he charged down a clearance from Berisha only to see the ball skew out of reach.

Chances were few and far between in a far more tense second half and Lazio striker Miroslav Klose, notably, was almost invisible before being replaced by Felip Djordjevic seven minutes from time.

Instead, Antonio Candreva and Anderson were running the show for the Biancocelesti, albeit with little reward.

Allegri replaced Pogba with Pereyra on 78 minutes and his freshness told immediately, the Argentinian tracking back to dispossess Anderson as the Brazilian held possession in a dangerous three on three.

Lazio spurned a great chance to claim a late winner, however, when Filip Djordjevic made a complete mess of a one on one with Storari.

Matri, who replaced Llorente six minutes from time, had the ball in the net moments after his arrival only for the goal to be ruled offside.

Lazio spurned another great chance to clinch the Cup when Djordjevic turned and fired a drive which beat Storari only to come off the near post and rebound across the goalmouth.

But Matri, who has played for four different clubs since joining Juventus in 2011, made the most of his opportunity when Tevez did well to control a long ball.

Tevez did well to control and drew two defenders before laying off for Matri to fire inside Berisha's near post to send the Curva Nord into raptures.