27' - CHANCE! Kramer with a shot on goal, but Mbolhi is there to save! The second ball is whipped back across the face of goal, but there's no-one there to convert!
25' - Schurrle with space down the right, but the Algerian defense block off his attempt on goal.
24' - Algeria with tired legs as they try, and try again, to break down a stubborn German backline.
22' - Germany taking the time, naturally, each time the ball goes out of play. Just eight minutes left.
20' - Slimani caught off-side, yet the crowd jeer loudly as they give their vocal backing to the African underdogs.
16' - Philipp Lahm cautioned for a tug back on Brahimi. Algeria with a free-kick 35 yeards out, but it bounces just in front of Neuer who gathers.
15' - The Fennec Foxes get us underway. Can they find that elusive goal?
13' - Germany still on the front foot. They have a corner, but there's no-one in the box as they pass back and keep possession.
9' - Algeria SUB: Djabou (ON) for Soudani (OFF)
9' - Muller with a strike from the edge of the box, but it's wide!
6' - It's the skipper's last action as he is replaced by Bougherra for the African nation.
4' - Algeria on the back foot after conceding as Germany look to double their advantage and make sure of the result.
2' - GOAL! Muller puts in a ball for Schurrle to convert in front of the posts! Germany with the advantage!
1' - And Germany get us underway in the first half of extra time!
94' - Mbohli safely gathers, and that's it! Into extra-time we go!
93' - Schurrle with a ball in from the right to win a German corner late-on.
92' - Goal-kick for Algeria as Schurrle can't reach a long ball down the right flank.
91' - Another German attack amounts to nothing as the frustration builds for the three-time champions.
90' - Four minutes of added time...
50' - End to end stuff as the corner is cleared and Algeria now break, but the German backline holds firm! Breathless opening to the second half!
49' - Algeria now with a corner, whhich Neuer initially spills but then quickly gathers. His quick release sends Schurrle off on his bike, and wins a corner.
47' - CLOSE! A German corner is taken short, but the cross is delievered in and Kroos heads his effort straight at Mbohli!
46' - 43 games since Germany were last held to a goalless draw at a World Cup! They're unbeaten in their last 14 internationals, so expect them to pile on the pressure in the second period.
45' - And we're underway!
German half-time substitute: Schurrle (ON) for Gotze (OFF)
And the referee blows his whistle to end the first half. Chances at both ends, but Mbolhi the busier of the two keepers.
45' - One minute to be added on...
44' - Germany ending the half the stronger of the two sides as they pile the pressure on the Algerian goal.
43' - CLOSE! Kroos with a left-footed strike from outside the box that flies narrowly wide!
42' - Halliche is first to go in the referee's book for a rash challenge in midfield.
40' - CHANCE! At the other end, double save from Mbolhi as he denies Kroos and then Gotze's follow-up effort!
38' - CHANCE! A long throw for Algeria falls at the feet of Mostefa, whose powerful effort is deflected out for a corner!
37' - Ozil with a swerving shot from range, which Mbolhi spills, but it's evetually dealt with by the Fennec Foxes.
36' - The Germans passing the ball around in midfield, trying to find a way through the resilient Algerian defense.
34' - CHANCE! Mustafi finds Muller with a low cross, but Germany's top-scorer at this year's World Cup headers wide!
31' - Ozil's shot on goal is blocked after a neat cut-back from Philipp Lahm.
30' - Still goalless after half an hour in Porto Alegre.
26' - Germans forced to pass back to Neuer after some good pressure from the Algerians in midfield.
25' - Africa's highest-ranked team at this year's Mundial holding their own against the European heavyweights...
23' - Mbolhi tips an Ozil chip over his goalposts for a German corner. The resulting set-piece is hoofed clear by the Algerian defense.
22' - Muller heads a difficult effort over the crossbar. He applaudes the cross.
21' - Germany have sent five of their substitutes out to warm up. Hmm...
20' - Neutrals in the stadium definitely behind the Fennec Foxes as they cheer loudly when Germany lose the ball.
16' - CHANCE! Algeria find the back of the net through a diving Slimani header, but it's offside!
14' - Sofiane Feghouli with a chance at the other end, wriggling his way through the German defense, but his effort from a difficult angle is wide.
10' - Loud roar from the crowd again as Slimani sets off once again, but this time the GErman defence holds firm as Mertesacker sticks out a foot. Slimani signalling his intent and showing off his pace early on.
8' - CHANCE! Neuer comes racing off his line and tackles the on-rushing Islam Slimani way outside the box with an open goal left behind him! Concedes a corner, which is easily dealt with. The Bayern shot-stopper was lucky there...
6' - Mustafi drills in a ball from the right, but again Mbolhi is there to snuff out the danger.
3' - Early touch for Manuel Neuer who collects an Algerian long-ball forward.
2' - Germany with the majority of the possession in the early satges. Mustafi caught off-side on the right.
1' - And the Brazilian official gets us underway! Germany in their white strip, Algeria in green.
Germany topped Group G with two wins and a draw, their only blemish a 2-2 draw with African giants Ghana. Algeria qualified second from Group H with one win, one draw and a loss, hanging on for a point in their final fixture against Russia to seal progress to the Last 16 for the first time in their history.
Germany are gunning for their 13th World Cup quarter-final appearance, but have history against them, having never beaten the Fennec Foxes - they lost against the Algerians in a friendly in 1964, while again suffering a defeat to the African nation in their World Cup group stage encounter in 1982.
Borussia Dortmund defender Mats Hummels is the only player unavailable from either side due to flu, while fellow defender Benedikt Howedes is the only player in either starting eleven to be sitting on a yellow card.
Germany XI: Neuer, Howedes, Schweinsteiger, Ozil, Muller, Lahm (c), Mertesacker, Kroos, Gotze, Boateng, Mustafi
Algeria XI: Mbolhi, Ghoulam, Belkalem, Halliche (c), Lacen, Feghouli, Slimani, Soudani, Taider, Mandi, Mostefa